Systems and methods for reducing pressure at an outflow of a duct

ABSTRACT

Various systems and methods are provided for reducing pressure at an outflow of a duct such as the thoracic duct or the lymphatic duct. A catheter system can include a catheter shaft configured to be at least partially implantable within a patient&#39;s vein, a flexible membrane attached to the catheter shaft, the flexible membrane being a collapsible, tube-like member having a lumen extending therethrough, and a single selectively deployable restriction member formed over a portion of the flexible membrane at substantially a midpoint between a proximal end of the flexible membrane and a distal end of the flexible membrane, the restriction member being configured to control a size of the lumen so as to direct a controlled volume of fluid from an upstream side of the restriction member to a downstream side the restriction member.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to U.S. application Ser. No.15/909,290, filed Mar. 1, 2018, which claims priority to U.S.Provisional Application No. 62/466,191, filed Mar. 2, 2017, the contentsof which are incorporated by reference.

FIELD

The present disclosure relates generally to systems and methods forreducing pressure at an outflow of a duct.

BACKGROUND

The lymphatic system is part of the circulatory system in conjunctionwith the arterial and venous systems. A primary function of thelymphatic system is to drain excessive interstitial fluid back into thevenous system at two main locations: the thoracic duct and the lymphaticduct, which drain into the left and right subclavian veins,respectively.

Under normal circulatory conditions of the arterial and venous systemsthe interstitial fluid volume balance is maintained and the lymph fluidis cleared back through the lymphatic system. In pathological conditionssuch as Acute Cardiogenic Pulmonary Edema and chronic heart failure, thecapillary hydrostatic pressure and the venous pulmonary pressure canbecome elevated and fluid flows excessively out of the blood vessels andinto the interstitial and alveolar spaces. The pressure gradient betweenthe initial lymphatics and at the outflow of the thoracic duct and thelymphatic duct is reduced and the lymphatic system cannot clear theadditional fluid which accumulates in the air spaces of the lungs. Thisis a life threatening condition as gas exchange is impaired to theextent that it may lead to respiratory failure.

Current treatment methods require extended hospitalization and treatmentwith loop diuretics and/or vasodilators. Oftentimes patients must alsoreceive supplemental oxygen or, in more extreme cases, requiremechanical ventilation. Many of these treatment methods are less thanideal because the edema is not always alleviated rapidly enough and formany patients renal function is adversely affected. A significantpercentage of patients do not respond to this treatment and asignificant percentage must be readmitted to a hospital within thirtydays.

A significant problem with current treatment protocol is that it isbased on the need to reduce intravascular blood pressure to moveinterstitial and lymphatic fluid back into the vasculature. Thereduction of intravascular blood pressure may lead to hypotension andmay activate the Renin Angiotensin Aldosterone System, which may leadback to an increase in blood pressure or to worsening of renal function.Eventually, this cycle leads to diuretic resistance and the worsening ofrenal function in almost 30% of admitted patients. The lymphatic systemcan directly drain fluids from the interstitial compartment into theintravascular compartment and by such to relief edema.

The lymphatic system drains the interstitial fluids via the thoracicduct and right lymphatic duct that drain into the region around thebifurcation of the left subclavian vein and left internal jugular veinfor the thoracic duct and into the bifurcation of the right internaljugular vein and right subclavian vein for the right lymphatic duct.However, in conditions such as acutely decompensated heart failure thelymphatic return is reduced as a result of elevated central venouspressure (CVP). Therefore, as a result of the elevated CVP, thelymphatic return is greatly reduced.

Accordingly, there remains a need for improved systems and methods forreducing pressure at an outflow of a duct such as the thoracic duct orthe lymphatic duct.

SUMMARY

Systems and methods are provided for reducing pressure at an outflow ofa duct, such as the thoracic duct or the lymphatic duct, and other partsof the venous system. Systems and methods for reducing venous pressureare provided. An indwelling catheter can be configured to be at leastpartially implanted within a vein of a patient in the vicinity of anoutflow port of a duct of the lymphatic system. The catheter isconfigured to provide a tunnel or lumen a blood flow through which iscontrolled. A size of the lumen is controlled so as to cause the heart,during its diastolic phase, to pump in (suck) blood harder therebyreducing pressures within the heart and at an outlet of a duct.

In certain aspects, the invention provides a catheter system. Thecatheter system includes a catheter shaft configured to be at partiallyimplanted within a blood vessel of a patient, an impeller assemblydisposed at a distal portion of the catheter shaft, a flexible membraneconnected to the impeller assembly, and a selectively deployablerestrictor attached to the distal portion via the flexible membrane.Deployment of the restrictor causes the flexible membrane to assume atapered configuration, defining a tapered lumen extending through therestrictor, the flexible membrane, and at least a portion of theimpeller assembly. The system may include an inflation lumen extendingat least partially through the catheter shaft, the at least oneinflation lumen being in fluid communication with the restrictor. Insome embodiments, the restrictor comprises a selectively expandableballoon coupled to an outer wall of the flexible membrane.

The restrictor may control the size of the tapered lumen by constrictingat least a portion of the flexible membrane when the restrictor is in anexpanded configuration. The flexible membrane may be oriented so as tobe substantially parallel to the catheter shaft.

In certain embodiments, at least a portion of the tapered lumen has adiameter from about 1 mm to about 4 mm when the restrictor is in anexpanded configuration. A diameter of the catheter shaft may be, e.g.,from about 4 Fr to about 9 Fr. Preferably, the blood vessel is one of aninternal jugular vein and a subclavian vein.

The restrictor may be mounted on a support ring at a proximal end of thetapered membrane, wherein the support ring comprises a guide channelholding a drive shaft of the impeller. The impeller housing may havewindows along a distal portion thereof. Preferably, when the distalportion is in the blood vessel and the restrictor is deployed and theimpeller is driven, the impeller draws blood through the tapered lumen.

The catheter system may include an atraumatic tip extending distally ofthe impeller housing; a driveshaft extending at least partially throughthe elongate member; or both. Optionally, the system may include aproximal assembly, the proximal assembly comprising a sheath (e.g., witha second restrictor) through which the elongate member is slideablydisposed.

In related aspects, the invention provides a method of treating reducingpressure at an outflow of a duct. The method includes positioning, in ablood vessel near an output of a duct, a device comprising a taperedlumen and pumping blood from a wide end of the tapered lumen to a narrowend to thereby lower pressure near the output of the duct. Preferably,the device has a restrictor with an opening therethrough and a housingmember, and the tapered lumen is provided by a flexible membrane thattapers from the opening to the housing member, and further wherein theblood is pumped by operating an impeller within the device. Therestrictor occludes the blood vessel (e.g., a jugular vein or asubclavian vein) but for the opening therethrough. In certainembodiments, the housing member houses the impeller, the device furthercomprising an elongate driveshaft extending proximally from theimpeller, wherein the blood flows out of the housing member via one ormore aperture along the side of the housing member. Preferably, therestrictor comprises an inflatable balloon and the method furthercomprises inflating the balloon when the device is positioned in thebody lumen.

In some aspects, a catheter system configured to be placed within a veinof a patient is provided that in some embodiments includes a cathetershaft, a flexible membrane, and a single selectively deployablerestriction member. The catheter shaft is configured to be at leastpartially implantable within a patient's vein. The flexible membrane isattached to the catheter shaft, and the flexible membrane is acollapsible, tube-like member having a lumen extending therethrough. Thesingle selectively deployable restriction member is formed over aportion of the flexible membrane at substantially a midpoint between aproximal end of the flexible membrane and a distal end of the flexiblemembrane, the restriction member being configured to control a size ofthe lumen so as to direct a controlled volume of fluid from an upstreamside of the restriction member to a downstream side the restrictionmember.

The catheter system can vary in different ways. For example, thecatheter can be an implantable catheter. The restriction member can beconfigured to control the size of the lumen so as to direct thecontrolled volume of fluid from the upstream side of the restrictionmember to the downstream side the restriction member by causing apumping force of the heart during diastole to be increased.

In at least some embodiments, the catheter system includes at least oneinflation lumen extending at least partially through the catheter shaft,the at least one inflation lumen being in fluid communication with therestriction member.

In at least some embodiments, the flexible membrane is oriented so as tobe substantially parallel to the catheter shaft.

In at least some embodiments, the restriction member includes aselectively expandable balloon coupled to an outer wall of the flexiblemembrane. In at least some embodiments, the balloon can be configured,in an expanded configuration, to expand at least in part inwardlytowards the flexible membrane so as to at least partially constrict themembrane. For example, in some embodiments, the balloon is configured,in the expanded configuration, to have at least one bulging feature atleast partially constricting the membrane.

In at least some embodiments, at least a portion of the lumen has adiameter from about 1 mm to about 4 mm when the restriction member is inan expanded configuration. A diameter of the catheter shaft can be fromabout 4 Fr to about 9 Fr.

The vein can be one of an internal jugular vein and a subclavian vein.The restriction member can be configured to control the size of thelumen by constricting at least a portion of the flexible membrane whenthe restriction member is in an expanded configuration.

In other aspects, a catheter system configured to be implantable withina vein of a patient is provided that in some embodiments includes acatheter shaft, a selectively deployable restriction member, and a flowregulation component. The catheter shaft is configured to be at leastpartially implantable within a patient's vein and having a lumenextending therethrough. The selectively deployable restriction member isformed over a portion of the catheter shaft and has the lumen extendingtherethrough, the restriction member being configured to be activated toat least partially occlude the vein. The flow regulation componentdisposed proximally to the restriction member and configured to controla volume of fluid from an upstream side of the restriction member to adownstream side the restriction member.

The catheter system can vary in different ways. For example, the vein isone of an internal jugular vein and a subclavian vein. As anotherexample, the restriction member is a selectively expandable balloon.

In another aspect, a medical method is provided that in some embodimentsinvolves implanting a catheter within a vein of a patient, the catheterhaving coupled thereto a selectively deployable single restrictionmember that has a lumen extending therethrough, the restriction memberbeing positioned at a location within the vein that is upstream of anoutflow port of a duct of the patient's venous system. The method alsoincludes actuating the restrictor to move the restrictor from a relaxedconfiguration to an activated configuration thereby limiting fluid flowwithin the vein and past the single restriction member so as to create alow pressure region within the vein downstream of the restrictor.

The method can vary in different ways. For example, the method caninclude creating blood flow restriction upstream of the singlerestriction member so as to create the low pressure region downstream ofthe single restriction member. As another example, a pressure upstreamof the single restriction member can be greater than a pressuredownstream of the single restriction member. As a further example, apressure in the low pressure region can be substantially the same as apressure in other parts of the patient's venous system except a part ofthe patient's venous system upstream of the single restriction member.

In at least some embodiments, limiting fluid flow within the vein andpast the single restriction member includes controlling a volume offluid through the lumen.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a schematic cross-sectional view of a catheter implanted in avein of a patient.

FIG. 2 is a perspective, partially transparent view of a distal portionof another embodiment of a catheter.

FIG. 3 is a perspective, partially transparent view of a distal portionof yet another embodiment of a catheter.

FIG. 4 is a partial cross-sectional view of the distal portion of thecatheter of FIG. 3 .

FIG. 5 is a cross-sectional view of the distal portion of the catheterof FIG. 3 .

FIG. 6 is a schematic version of the cross-sectional view of FIG. 5 .

FIG. 7 is a perspective, partially transparent view of a distal portionof yet another embodiment of a catheter.

FIG. 8 is a partial cross-sectional view of the distal portion of thecatheter of FIG. 7 .

FIG. 9 is a schematic version of the cross-sectional view of FIG. 8 .

FIG. 10 is a perspective view of one embodiment of a catheter system.

FIG. 11 is perspective view of a flexible membrane and catheter shaft ofthe catheter system of FIG. 10 .

FIG. 12 is another perspective view of the flexible membrane andcatheter shaft of the catheter system of FIG. 11 .

FIG. 13 is a perspective view of a restrictor of the catheter system ofFIG. 10 attached to the flexible membrane of the catheter system.

FIG. 14 is side, partial cross-sectional view of flattened edges of therestrictor of FIG. 11 .

FIG. 15 is a side, partial cross-sectional view of folded edges ofanother embodiment of a restrictor.

FIG. 16 is a cross-sectional schematic view of a pattern for forming arestriction member with a torus shape.

FIG. 17 is cross-sectional schematic view of a restriction member formedusing the pattern of FIG. 16 and of a sleeve on which the restrictionmember is assembled.

FIG. 18 is a cross-sectional schematic view of the restriction member ofFIG. 17 following inversion of legs thereof.

FIG. 19 is a perspective view of a distal portion of the catheter systemof FIG. 10 .

FIG. 20 is a side view of another distal portion of the catheter systemof FIG. 10 .

FIG. 21 is a perspective view of a proximal portion of the cathetersystem of FIG. 10 .

FIG. 22 is a side view of the catheter system of FIG. 10 .

FIG. 23 is a distal end view of the catheter system of FIG. 10 .

FIG. 24 is a cross sectional view of the catheter system of FIG. 10 witha flexible membrane of the catheter system in an expanded configuration.

FIG. 25 is a cross sectional view of the catheter system of FIG. 10having a restrictor thereof in an activated configuration.

FIG. 26 is a cross sectional view of the catheter system of FIG. 10having a restrictor thereof in a relaxed configuration.

FIG. 27 is a schematic, partially cross-sectional view of a portion ofthe catheter system of FIG. 10 implanted in a patient;

FIG. 28 is a perspective, partially cross-sectional view of anotherportion of the catheter system of FIG. 27 implanted in the patient.

FIG. 29 is another perspective, partially cross-sectional view of thecatheter system of FIG. 27 implanted in the patient.

FIG. 30 is a side cross-sectional view of a distal portion of thecatheter system of FIG. 10 .

FIG. 31 is a cross-sectional view of the distal portion of the cathetersystem of FIG. 30 .

FIG. 32 is a schematic, partially cross-sectional view of a distalportion of the catheter system of FIG. 10 introduced into a vein.

FIG. 33 is a perspective view of an implantable catheter system.

FIG. 34 is an exploded view of the implantable system of FIG. 33 .

FIG. 35 illustrates a distal assembly of the implantable system of FIG.33 .

FIG. 36 is a perspective view of the distal assembly of the cathetersystem.

FIG. 37 is a back view back view of the distal assembly.

FIG. 38 shows a restrictor that regulates jugular flow and pressure.

FIG. 39 is cross-section through a portion of the catheter.

FIG. 40 shows an impeller for a catheter of the disclosure.

FIG. 41 is a side view of an impeller housing.

FIG. 42 is a perspective view of the impeller housing.

FIG. 43 shows the multi-strut support ring.

FIG. 44 is a detail view of the conical membrane.

FIG. 45 shows the flexible, atraumatic tip.

FIG. 46 is a perspective view of the implantable system of FIG. 33 ,showing the implantable system implanted in a body; and

FIG. 47 is a perspective view of another implantable system, showing theimplantable system implanted in a body.

FIG. 48 is a schematic view of a portion of the venous system of apatient.

FIG. 49 is a schematic view of a portion of a catheter implanted in thevenous system of FIG. 48 .

FIG. 50 is a schematic view of a portion of the venous system of apatient, illustrating locations at which a catheter having a singlerestriction member can be placed;

FIG. 51 is a schematic view of one embodiment of a catheter having asingle restriction member.

FIG. 52 is a schematic, partially transparent view of the catheter ofFIG. 51 .

FIG. 54 is another schematic view of the catheter of FIG. 51 ,illustrating a blood flow into the single restriction member and a veinwall.

FIG. 54 is a first step in a process of activation of a balloon and aflexible membrane of a catheter.

FIG. 55 is a second step in a process of activation of a balloon and aflexible membrane of a catheter.

FIG. 56 is a third step in a process of activation of a balloon and aflexible membrane of a catheter.

FIG. 57 is a cross-section view through a catheter system with a singlerestrictor, or balloon.

FIG. 58 is a schematic view of another embodiment of a catheter having asingle restriction member.

FIG. 59 is a schematic, partially transparent view of an embodiment of acatheter having a single restriction member.

FIG. 60 is a schematic, partially transparent view of an embodiment of acatheter having a single restriction member and a flexible membrane.

FIG. 61 is a schematic, partially transparent view of another embodimentof a catheter having a single restriction member and a flexiblemembrane.

FIG. 62 diagrams a method of implanting a catheter.

DETAILED DESCRIPTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those skilled in the art will understand that the devices andmethods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention.

Reference throughout the specification to “various embodiments,” “someembodiments,” “one embodiment,” or “an embodiment,” or the like, meansthat a particular feature, structure, or characteristic described inconnection with the embodiment is included in at least one embodiment.Thus, appearances of the phrases “in various embodiments,” “in someembodiments,” “in one embodiment,” or “in an embodiment,” or the like,in places throughout the specification are not necessarily all referringto the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments. Thus, the particular features, structures, orcharacteristics illustrated or described in connection with oneembodiment may be combined, in whole or in part, with the featuresstructures, or characteristics of one or more other embodiments withoutlimitation.

It will be appreciated that the terms “proximal” and “distal” may beused throughout the specification with reference to a clinicianmanipulating one end of an instrument used to treat a patient. The term“proximal” refers to the portion of the instrument closest to theclinician and the term “distal” refers to the portion located furthestfrom the clinician. It will be further appreciated that for concisenessand clarity, spatial terms such as “vertical,” “horizontal,” “up,” and“down” may be used herein with respect to the illustrated embodiments.However, surgical instruments may be used in many orientations andpositions, and these terms are not intended to be limiting and absolute.

Further, in the present disclosure, like-named components of theembodiments generally have similar features, and thus within aparticular embodiment each feature of each like-named component is notnecessarily fully elaborated upon. Additionally, to the extent thatlinear or circular dimensions are used in the description of thedisclosed systems, devices, and methods, such dimensions are notintended to limit the types of shapes that can be used in conjunctionwith such systems, devices, and methods. A person skilled in the artwill recognize that an equivalent to such linear and circular dimensionscan easily be determined for any geometric shape. Sizes and shapes ofthe systems and devices, and the components thereof, can depend at leaston the anatomy of the subject in which the systems and devices will beused, the size and shape of components with which the systems anddevices will be used, and the methods and procedures in which thesystems and devices will be used.

Various systems and methods are provided for reducing pressure at anoutflow of a duct such as the thoracic duct or the lymphatic duct. Ingeneral, the systems and methods may be effective to reduce edemaconditions, such as pulmonary edema, in a patient by lowering an outflowpressure in a region around the patient's thoracic/lymphatic ductoutflow. As a result of lowering the outflow pressure at the thoracicand/or lymphatic ducts, higher lymphatic return will be achieved,enabling the lymphatic vessel flow to be at or near normal levels. Thesystems and methods may be effective to rapidly alleviate conditions ofthe edema and increase the patient response rate. In an exemplaryembodiment, the systems and methods may be particularly useful to treatacute pulmonary edema; however a person skilled in the art willappreciate that the systems and methods can be used in variousprocedures for treating a lymphatic system fluid clearance imbalance.

An indwelling catheter can be configured to be at least partiallyimplanted (e.g., partially implanted or fully implanted) within a veinof a patient in the vicinity of an outflow port of a duct of thelymphatic system, e.g., in the vicinity of an outflow port of thethoracic duct or in the vicinity of an outflow port of the lymphaticduct. Exemplary materials from which the catheter can be made includepolyurethanes. The catheter can include first and second restrictors(also referred to herein as “restriction members”) each configured to atleast partially occlude the vein within which the catheter is implantedand thus to restrict fluid flow within the vein when the restrictors areactivated. The restrictors can each be configured to move between anactivated configuration, in which the restrictor occludes the vein, anda relaxed configuration, in which the restrictor does not occlude thevein. The restrictors can each be in the relaxed configuration duringimplantation of the catheter to ease introduction of the catheter intothe patient's body and into the vein. Each of the restrictors caninclude a balloon configured to be inflated where in the relaxedconfiguration the balloon is not inflated and in the activatedconfiguration in which the balloon is inflated. The restrictors can bemade from any one or more of a variety of materials configured to expandupon the delivery of a fluid thereto and to contract upon the withdrawalof the fluid. Exemplary materials from which the balloon can be madeinclude polymeric materials such as PEBAX, silicones, polyurethanes, andnylons. The catheter can include at least one inflation lumen throughwhich an inflation fluid (e.g., air, liquid, etc.) can be introduced toinflate/deflate the restrictors. The at least one inflation lumen caninclude one lumen in fluid communication with both of the restrictorssuch that the restrictors can be simultaneously inflated/deflated, orcan include first and second lumens with the first lumen in fluidcommunication with the first restrictor and the second lumen in fluidcommunication with the second restrictor such that the restrictors canbe selectively inflated simultaneously or sequentially. The catheter caninclude a pump, such as an axial motor pump, configured to pump fluidthrough the catheter. The catheter can be coupled to a motor configuredto drive the pump. The motor can be included in the catheter (e.g.,within a shaft of the catheter) and be configured to be implanted withthe catheter, or the motor can be located outside of the catheter (e.g.,outside of the catheter's shaft) and be configured to be located outsideof the patient rather than be implanted therein.

In one embodiment of using the catheter, the catheter can be positionedat a desired location within the vein. The first and second restrictorscan then each be activated (simultaneously or sequentially) to move fromthe relaxed configuration to the activated configuration. The first andthe second restrictors, when activated so as to provide two occlusionswithin the vein, define a low pressure zone between the first and secondrestrictors within a portion of the vein in which the catheter ispositioned. Higher pressure zones accordingly exist on either side ofthe restrictors. The motor can drive the pump to induce the low pressurezone by causing fluid to be pumped through the catheter. The catheterand the restrictors can be positioned within the vein such that the lowpressure zone is adjacent to an outflow port of a duct (e.g., thethoracic duct or the lymphatic duct) to allow fluid to pass from thelymph duct outflow port to the portion of the catheter housed within thevein so that fluid can flow out of the catheter.

In at least some embodiments, the restrictor(s) of a catheter can beinflated and deflated from time to time to enable free flow of blood ina patient's vein in which the restrictor(s) are positioned and thusenable the system to stop working for a period of time. This period oftime can be required in such treatments to allow for the assessment ofthe patient's clinical condition, allow the patient to undergo othertreatments or enable him to go to the bathroom and/or to wash anystagnation points that might have occurred.

The catheters described herein can be configured to be placed in apatient's body for up to about seventy-two hours, e.g., the catheter canbe indwelled in the body for up to about seventy-two hours. The cathetersystems described herein that include the catheters can be operated in atreatment time period in a range of about 6 to 8 hours. At the end ofeach treatment period, the restrictors are deflated, the catheter can befilled with a heparin catheter locking solution, and an assessment ofthe patient's clinical condition can be performed. The catheter systemcan be operated again if desired by medical personnel. Within theindwelling period of the catheter, a number of treatment periods can bein a range of 3 to 6 cycles, e.g., for a maximum of about forty hours ofoperation within a seventy-two hour indwelling period.

A person skilled in the art will appreciate that the systems and methodsdisclosed herein can be used with a variety of surgical devices,including measuring devices, sensing devices, locator devices, insertiondevices, etc.

Furthermore, various systems and methods are provided for reducingpressure at an outflow of a duct such as the thoracic duct or thelymphatic duct. In general, the systems and methods may be effective toreduce edema conditions, such as pulmonary edema, in a patient bylowering an outflow pressure in a region around the patient'sthoracic/lymphatic duct outflow. As a result of lowering the outflowpressure at the thoracic and/or lymphatic ducts, higher lymphatic returnwill be achieved, enabling the lymphatic vessel flow to be at or nearnormal levels. The systems and methods may be effective to rapidlyalleviate conditions of the edema and increase the patient responserate. In an exemplary embodiment, the systems and methods may beparticularly useful to treat acute pulmonary edema. However, a personskilled in the art will appreciate that the systems and methods can beused in various procedures for treating a lymphatic system fluidclearance imbalance.

An indwelling catheter can be configured to be at least partiallyimplanted (e.g., partially implanted or fully implanted) within a veinof a patient in the vicinity of an outflow port of a duct of thelymphatic system, e.g., in the vicinity of an outflow port of thethoracic duct or in the vicinity of an outflow port of the lymphaticduct. Exemplary materials from which the catheter can be made includepolyurethanes. The catheter can include first and second restrictors(also referred to herein as “restriction members”), at least one ofwhich is configured to at least partially occlude the vein within whichthe catheter is implanted and thus to restrict fluid flow within thevein when at least one of the restrictors is activated. The restrictorscan each be configured to move between an activated configuration, inwhich the restrictor occludes the vein, and a relaxed configuration, inwhich the restrictor does not occlude the vein. The restrictors can eachbe in the relaxed configuration during implantation of the catheter toease introduction of the catheter into the patient's body and into thevein. Each of the restrictors can include a balloon configured to beinflated, where in the relaxed configuration the balloon is not inflatedand in the activated configuration in which the balloon is inflated.

The restrictors can be made from any one or more of a variety ofmaterials configured to expand upon the delivery of a fluid thereto andto contract upon the withdrawal of the fluid. Exemplary materials fromwhich the balloon can be made include polymeric materials such as PEBAX,silicones, polyurethanes, and nylons. The catheter can include at leastone inflation lumen through which an inflation fluid (e.g., air, liquid,etc.) can be introduced to inflate/deflate the restrictors. The at leastone inflation lumen can include one lumen in fluid communication withboth of the restrictors such that the restrictors can be simultaneouslyinflated/deflated, or can include first and second lumens with the firstlumen in fluid communication with the first restrictor and the secondlumen in fluid communication with the second restrictor such that therestrictors can be selectively inflated simultaneously or sequentially.The catheter can include a pump, such as an axial motor pump, configuredto pump fluid through the catheter. The catheter can be coupled to amotor configured to drive the pump. The motor can be included in thecatheter (e.g., within a shaft of the catheter) and be configured to beimplanted with the catheter, or the motor can be located outside of thecatheter (e.g., outside of the catheter's shaft) and be configured to belocated outside of the patient rather than be implanted therein.

The catheter can be positioned at a desired location within the vein.The first and second restrictors can then each be activated(simultaneously or sequentially) to move from the relaxed configurationto the activated configuration. The first and the second restrictors,when activated so as to provide, in combination with other components,occlusion within the vein, define a low pressure zone between first andthe second restrictors within a portion of the vein in which thecatheter is positioned. Higher pressure zones accordingly exist oneither side of the restrictors. The motor can drive an impeller toinduce the low pressure zone by causing fluid to be pumped through thecatheter. The catheter and the restrictors can be positioned within thevein such that the low pressure zone is adjacent to an outflow port of aduct (e.g., the thoracic duct or the lymphatic duct) to allow fluid topass from the lymph duct outflow port to the portion of the catheterhoused within the vein so that fluid can flow out of the catheter.

In at least some embodiments, at least one of the restrictors of acatheter can be inflated and deflated from time to time to enable freeflow of blood in a patient's vein in which the restrictor(s) arepositioned and thus enable the system to stop working for a period oftime. This period of time can be required in such treatments to allowfor the assessment of the patient's clinical condition, allow thepatient to undergo other treatments or enable him to go to the bathroomand/or to wash any stagnation points that might have occurred. Each ofthe restrictors can be configured and operated as described, forexample, in U.S. application Ser. No. 14/625,930 entitled “System AndMethod For Treating Pulmonary Edema,” filed Feb. 19, 2015, and in U.S.application Ser. No. 14/726,715 entitled “Systems and Methods forTreating Pulmonary Edema,” filed Jun. 1, 2015, the content of each ofwhich is incorporated by reference herein in its entirety. In addition,some features of the catheter system described herein can be implementedas described in U.S. App. Publ. No. 2016/0331378 entitled “Systems andMethods for Reducing Pressure at an Outflow of a Duct,” filed May 10,2016, the content of which is incorporated by reference herein in itsentirety.

In some embodiments, the catheters can be configured to be placed in apatient's body for up to about seventy-two hours, e.g., the catheter canbe indwelled in the body for up to about seventy-two hours. The cathetersystems are configured to be able to be accurately fixated and deployedin a patient's body. The systems can be configured to be convenientlyplaced to a desired location in a patient (torque can be applied), andthey possess compatibility with a guide wire and sheath, ability toovercome leads and leads effects, ability to automatically maintain aworking point for 72 hours (<5 mmHg at the isolated zone), and abilityto measure pressure at the pressure reduction zone. It should beappreciated, however, that in other instances a catheter system inaccordance with the described techniques can be indwelled in the bodyfor duration of time greater than seventy-two hours—for example, severaldays or weeks. The system can be configured to maintain hemostasis.

In some embodiments, a catheter can include a single restrictorconfigured to at least partially occlude the vein within which thecatheter is implanted and thus to restrict fluid flow within the veinwhen the restrictor is activated. In such embodiments, a pressure at thelymphatic outflow can be reduced by inflating the single restrictor suchas a proximal balloon, without the need to inflate a distal balloon.However, it should be appreciated that the catheter can include bothdistal and proximal balloons and only the proximal one of the balloonscan be used.

A person skilled in the art will appreciate that the systems and methodsdisclosed herein can be used with a variety of surgical devices,including measuring devices, sensing devices, locator devices, insertiondevices, etc.

FIG. 1 illustrates one embodiment of a catheter 1 that includes at leastone restrictor 2 a, 2 b. The at least one restrictor includes first andsecond restrictors 2 a, 2 b in this illustrated embodiment, which eachinclude a balloon configured to be inflated (corresponding to anactivated configuration) and deflated (corresponding to a relaxedconfiguration). The first and second restrictors 2 a, 2 b can be spaceda distance apart from one another along a longitudinal length of thecatheter 1 such that one of the restrictors 2 b is more distal than theother of the restrictors 2 a. The distance between the first and secondrestrictors 2 a, 2 b can define a length of a low pressure zone that canbe created when the catheter 1 is implanted within a vein. FIG. 1 showsthe catheter 1 positioned within an internal jugular vein 3 of a patientwith the distal restrictor 2 b positioned distal to an outflow port 4 pof the patient's thoracic duct 4 and the proximal restrictor 2 apositioned proximal to the outflow port 4 p of the patient's thoracicduct 4. The low pressure zone defined between the proximal and distal(first and second) restrictors 2 a, 2 b can thus be located adjacent theoutflow port 4 p of the thoracic duct 4. The proximal restrictor 2 abeing positioned proximal to (e.g., upstream) of the outflow port 4 p ofthe thoracic duct 4 may help prevent back flow from the patient'ssubclavian vein 5 while providing the low pressure zone and benefit(s)thereof. The catheter 1 can be similarly positioned on a right side ofthe patient with the distal restrictor 2 b positioned distal to anoutflow port of the patient's subclavian vein 5 and an outflow port ofthe patient's lymphatic duct (not shown) and the proximal restrictor 2 apositioned proximal to the outflow port of the patient's subclavian vein5 and the outflow port of the patient's lymphatic duct.

The catheter 1 can include at least one inflation lumen (omitted fromFIG. 1 for clarity of illustration) configured to facilitate inflationof the first and second restrictors 2 a, 2 b, e.g., to facilitatemovement of the restrictors 2 a, 2 b between the activated and relaxedconfigurations. The first and second restrictors 2 a, 2 b are shown inthe activated configuration in FIG. 1 with the first and secondrestrictors 2 a, 2 b each abutting an internal surface of the jugularvein 3 so as to provide two, spaced-apart occlusions therein.

The catheter 1 can include a shaft 7 having a lumen 7L, as shown in thisillustrated embodiment, configured to communicate fluid therethrough soas to accommodate the flow of fluid in a vein in which the catheter 1 isimplanted. The shaft 7 can have a variety of sizes, such as having adiameter that is in the range of about 8 to 18 Fr (e.g., about 8 Fr,equal to or less than about 12 Fr, etc.) and having a length in therange of about 25 to 40 cm.

The first and second restrictors 2 a, 2 b can be attached to andsurround the shaft 7. The first and second restrictors 2 a, 2 b can eachbe formed in the shape of a torus, as in this illustrated embodiment, tofacilitate the surrounding of the shaft 1 and/or to help preventcompression of the restrictors 2 a, 2 b when they are moved radiallyoutward during expansion thereof and thereby thus overcoming a possibletendency for the restrictors 2 a, 2 b to collapse in response to anexternal pressure. The first and second restrictors 2 a, 2 b can,however, have other shapes.

The catheter 1 can have a first or distal suction inlet 8 d formedthrough the shaft's sidewall. The distal suction inlet can be incommunication with the lumen 7L so as to allow fluid to enter the lumen7L therethrough, as shown in FIG. 1 by four arrows at the distal suctioninlet 8 d pointing inward toward the lumen 7L. The distal suction inlet8 d can include any number of openings formed through the shaft'ssidewall. The openings can have any of a variety of configurations,e.g., slits, circular holes, ovular holes, rectangular slots, etc. Thedistal suction inlet 8 d can be located along the catheter'slongitudinal length at a position between the first and secondrestrictors 2 a, 2 b. The distal suction inlet 8 d can thus be locatedwithin the low pressure zone. In an exemplary embodiment, as shown inFIG. 1 , in use, the distal suction inlet 8 d can be positioned adjacentthe outflow ports 4 p, 5 p of the thoracic duct 4 and the subclavianvein 5 so as to allow fluid exiting the outflow ports 4 p, 5 p to enterthe catheter 1.

The catheter 1 can include a second or proximal suction inlet 8 p formedthrough the shaft's sidewall. The proximal suction inlet 8 p can be incommunication with the lumen 7L so as to allow fluid to enter thecatheter's lumen 7L therethrough, as shown in FIG. 1 by two arrows atthe proximal suction inlet 8 p pointing inward toward the lumen 7L. Theproximal suction inlet 8 p can include any number of openings formedthrough the shaft's sidewall. The openings can have any of a variety ofconfigurations, e.g., slits, circular holes, ovular holes, rectangularslots, etc. The proximal suction inlet 8 p can be located proximal tothe distal suction inlet 8 d and proximal to the first and secondrestrictors 2 a, 2 b. In an exemplary embodiment, as shown in FIG. 1 ,in use, the proximal suction inlet 8 p can be positioned proximal to theoutflow ports 4 p, 5 p of the thoracic duct 4 and the subclavian vein 5,e.g., upstream thereof. The proximal suction inlet 8 p may thus allowfor regular fluid flow through the jugular vein 3 even when the proximalrestrictor 2 a is activated and occluding the jugular vein 3.

The catheter 1 can include a distal end Id configured to be implantedwithin the patient's body (e.g., within the jugular vein 3, as shown inthis illustrated embodiment) and a proximal end 1 p configured to not beimplanted and instead be located outside the patient's body when thecatheter's distal end Id is implanted. The distal end Id of the catheter1 can be open so as to define a discharge opening of the catheter 1 thatallows fluid in the lumen 7L to exit the catheter 1 therethrough. Thedistal restrictor 2 b being positioned proximal to the discharge openingmay help prevent back flow of fluid exiting the catheter 1 through thedischarge opening. The distal restrictor 2 b can thus be positioned justproximal to the discharge opening to help maximize backflow prevention.The catheter's proximal end 1 p is configured to not be implanted and isshown outside of the patient's body in FIG. 1 . FIG. 1 also shows acontroller or motor 9 coupled to the catheter 1 and located outside ofand proximal to the catheter's proximal end 1 p so as to not be withinthe catheter's shaft 7 and to be located outside of the patient's body.Alternatively, as mentioned above, the catheter's proximal end 1 p canbe configured to be implanted, such as when the controller or motor 9 isincluded in the catheter's shaft 7.

The catheter 1 can include a pump configured to drive fluid flow throughthe catheter 1, e.g., through the lumen 7L thereof. The pump can have avariety of configurations. As in this illustrated embodiment, the pumpcan include an axial motor pump. The axial motor pump can generally beconfigured like an Archimedes' screw that drives fluid. The axial motorpump can include an impeller I and a drive shaft S (e.g., a cable or arod) each located in the catheter's shaft 7, e.g., in the lumen 7L. Alsoas in this illustrated embodiment, the impeller I can be located fullydistal to the proximal restrictor 2 a and can be located at leastpartially proximal to the second restrictor 2 b so as to be at leastpartially located within the low pressure zone and hence near the distalinlet opening. In this illustrated embodiment, the impeller I is fullylocated within the low pressure zone. The drive shaft S can extendlongitudinally through the catheter 1, e.g., through the lumen 7L, tothe controller or motor 9. The motor 9 can be configured to drive thedrive shaft S, e.g., to rotate the drive shaft S, and hence drive theimpeller I, e.g., rotate the impeller I. The drive shaft S can be asolid member, which may provide structural stability to the drive shaftS. Alternatively, the drive shaft S can be hollow, e.g., be cannulated.The drive shaft S being hollow can allow a guide wire to be advancedtherethrough, which may facilitate delivery of the catheter 1 into avein, as will be appreciated by a person skilled in the art, such as byallowing the guide wire to be introduced into a vein and the catheter 20to then be advanced over the guide wire (and into a sheath (not shown)of the system 10 advanced over the guide wire prior to the catheter 20being advanced over the guide wire, if the system 10 includes a sheath).For example, the guide wire can be introduced into the jugular vein 3(e.g., a Seldinger technique via a central venous access underultrasound guidance), and then the drive shaft S (and the catheter 1coupled thereto) can be advanced over the guide wire into the jugularvein 3.

The pump can be configured to pump fluid at a variety of rates. In anexemplary embodiment, the pump can be configured to pump fluid at a ratein a range of about 100 to 1000 ml/hour, which can provide a pressurereduction in the low pressure zone from a pressure in a range of about10 to 20 mmHg (the pressure in the higher pressure zones) to a pressurein a range of about 0 to 6 mmHg (e.g., in a range of about 2 to 4 mmHg,which is a typical normal level, or in a range of about 2 to 5 mmHg,which is also a typical normal level). In at least some embodiments, thepump can have a static, e.g., unchangeable, flow rate. The flow rate canthus be predictable and/or chosen for a specific patient. In otherembodiments, the pump can have an adjustable flow rate. The flow ratebeing adjustable can help the pump accommodate changes in the patient'scondition over time and/or allow the pump to be driven at a selectedrate for a particular patient. The flow rate can be adjustable in avariety of ways, as will be appreciated by a person skilled in the art,such as by being wirelessly adjusted using a user-operated controldevice located external to the patient and configured to wirelesslycommunicate with the pump (e.g., with the controller 9) to adjust theflow rate thereof.

In at least some embodiments, the controller 9 can be configured to bein electronic communication with at least one pressure sensor (notshown). A person skilled in the art will appreciate that a variety ofsuitable sensors can be used for monitoring pressure, such as centralvenous pressure (CVP) or other fluid pressure sensors, and bloodpressure sensors. The at least one pressure sensor can be implanted inthe patient as part of the pump, implanted in the patient as a separatecomponent from the pump, or the at least one pressure sensor can belocated external to the patient, such as by being on a skin surfacethereof. If not already a part of the pump so as to be in electroniccommunication therewith, the at least one pressure sensor can beconfigured to be in electronic communication with the pump over acommunication line such as a wired line or a wireless line. In anexemplary embodiment, two pressure sensors can be implanted in thepatient. One of the pressure sensors can be implanted between the firstand second restrictors 2 a, 2 b so as to be in the low pressure zone,and the other one of the pressure sensors can be implanted in the veineither proximal to the proximal restrictor 2 a (e.g., proximal to theproximal inlet) or distal to the distal restrictor 2 b (e.g., distal tothe discharge opening) so as to be in one of the higher pressure zones.The two sensors can thus allow a pressure differential to be determinedbetween the low pressure zone and the higher pressure zone. In otherembodiments, another number of pressure sensors can be implanted in thepatient (e.g., one, three, four etc.) and/or the pressure sensor(s) canbe implanted at other locations.

The catheter 1 can include at least one lumen (not shown) configured tofacilitate use of the pressure sensor(s), for example to facilitateplacement of the pressure sensor(s) and/or to be filled with a fluidsuch as saline to allow for external pressure measurement.

In addition to or instead of the one or more pressure sensors, thecontroller 9 can be configured to be in electronic communication with atleast one other type of sensor (not shown) configured to sense aparameter other than pressure. Examples of sensors that can be used tomeasure a parameter other than pressure include radio frequencytransmitters and receivers, fluid sensors, bio impedance sensors, heartrate sensors, breathing sensors, activity sensors, and optical sensors.Examples of the measured parameter include fluid amount (e.g., asmeasured by a fluid sensor, such as a fluid sensor placed in a lung tosense fluid amount in the lung), bio impedance (e.g., as measured by abio impedance sensor), heart rate (e.g., as measured by a heart ratesensor), breathing rate (e.g., as measured by a breathing sensor),patient activity level (e.g., as measured by an activity sensor), andorgan dimension (e.g., as measured by an optical sensor). The sensor canbe implanted in the patient as part of the pump, implanted in thepatient as a separate component from the pump (e.g., implanted in aninterstitial space around a lung, implanted at a junction of a rightsubclavian vein of a patient and an internal jugular vein of thepatient, implanted at a junction of a left subclavian vein of a patientand an internal jugular vein of the patient, etc.), or the sensor can belocated external to the patient, such as by being on a skin surfacethereof. If not already a part of the pump so as to be in electroniccommunication therewith, the non-pressure sensor(s) can be configured tobe in electronic communication with the pump over a communication linesuch as a wired line or a wireless line. The non-pressure sensor(s) caninclude one or more sensors. In embodiments including a plurality ofsensors, each of the sensors can be configured to measure the sameparameter as or a different parameter than any one or more of the othersensors.

The motor 9 can be included as part of the pump and can be configured tobe implanted in the patient with the pump, or, as in this illustratedembodiment, the motor 9 can be configured to be non-implantable. Themotor 9 being non-implantable can help the pump have a smaller sizeand/or can allow the pump to be driven by a more powerful motor sincethe motor 9 can be larger than an implantable motor.

The controller 9 can be included as part of the pump and can beconfigured to be implanted in the patient with the pump, or, as in thisillustrated embodiment, the controller 9 can be configured to benon-implantable. The controller 9 being part of the pump can help allowthe pump to be a self-contained system, although in such a controllerrequires space in the pump, which can increase a size of the pump. Thecontroller 9 being non-implantable can help the pump have a smaller sizeand/or can allow the pump to be controlled by a more powerful processorsince the processor can be more easily upgraded than if implanted withthe pump and/or since the processor's size can be less important whenoutside the pump as opposed to inside the pump.

The controller 9 can include any type of microprocessor or centralprocessing unit (CPU), including programmable general-purpose orspecial-purpose microprocessors and/or any one of a variety ofproprietary or commercially available single or multi-processor systems.The controller 9 can be a component of a control system that includesany number of additional components, such as a memory configured to canprovide temporary storage and/or non-volatile storage; a bus system; anetwork interface configured to enable the control system to communicatewith other devices, e.g., other control systems, over a network; and aninput/output (I/O) interface configured to connect the control systemwith other electronic equipment such as I/O devices (e.g., a keyboard, amouse, a touchscreen, a monitor, etc.) configured to receive an inputfrom a user.

The controller 9 can be configured to receive user input thereto tocontrol any of a variety of aspects related to the catheter 1, such asspeed of the motor 9 and ideal range of pressure for the low pressurezone.

In at least some embodiments, the pump can be configured to change itspumping rate (e.g., from zero to a non-zero value, from a non-zero valueto zero, or from one non-zero value to another non-zero value) based onpressure measured by the at least one pressure sensor. The controller 9can be configured to effect such change in response to the sensedpressure. If the measured pressure exceeds a predetermined thresholdmaximum pressure value, the pump can be configured to increase its pumprate (e.g., increase from zero or increase from some non-zero value) inan effort to decrease the pressure. For example, if the measuredpressure within the low pressure zone is too high (e.g., is above apredetermined threshold), the pump can increase its pump rate todecrease the pressure within the low pressure zone. For another example,if the measured pressure within the low pressure zone is below apredetermined threshold, the pump can decrease its pump rate to maintainor increase the pressure within the low pressure zone. For yet anotherexample, if a measured pressure differential between the low pressurezone and the higher pressure zone is not sufficiently great (e.g., isbelow a predetermined threshold), the pump can increase its pump rate toincrease the pressure differential.

In at least some embodiments, the catheter 1 can include only onerestrictor, the proximal restrictor 2 a. A higher pressure zone can thusbe proximal to the proximal restrictor, and a low pressure zone can bedistal to the proximal restrictor. The proximal restrictor 2 apositioned proximal to (e.g., upstream) of the outflow port 4 p of thethoracic duct 4 being the only restrictor of the catheter 1, instead ofthe distal restrictor 2 b positioned distal to (e.g., downstream) of theoutflow port 4 p of the thoracic duct 4, may help prevent back flow fromthe subclavian vein 5 while providing the low pressure zone andbenefit(s) thereof.

In at least some embodiments, the catheter 1 can have a soft atraumatictip at its distal end Id that is tapered in a distal direction and thatis flexible. The soft atraumatic tip may facilitate smooth, safeintroduction of the catheter 1 into the vein 3. Exemplary materials fromwhich the atraumatic tip can be made include polyurethanes. The cathetermay additionally include a flexible extension similar to a guide wiretip and/or have a hydrophilic coating, each of which may furtherfacilitate smooth, safe introduction of the catheter 1 into the vein 3.

In at least some embodiments, the proximal restrictor 2 a can beconfigured to only partially occlude the vein 3 in which the catheter 1is positioned when the proximal restrictor 2 a in its activatedconfiguration. This partial occlusion may facilitate normal fluid flowthrough the vein 3 even when the proximal restrictor 2 a is in theactivated configuration. In embodiments in which the proximal restrictor2 a is configured to only partially occlude the vein 3 when in itsactivated configuration, the catheter 1 can, but need not, include theproximal inlet 8 p to facilitate fluid flow through the vein 3. Thepartial occlusion can be achieved in a variety of ways. For example, theproximal restrictor 2 a can have at least one lumen or hole formedtherethrough configured to allow fluid flow therethrough when theproximal restrictor 2 a is in the activated configuration. For anotherexample, a maximum diameter of the proximal restrictor 2 a in theactivated configuration can be less than a maximum internal diameter ofthe vein 3 in which the catheter 1 is positioned to allow fluid flowaround an exterior of the proximal restrictor 2 a.

In at least some embodiments, the catheter 1 can include at least onelumen or tube (not shown) configured to pass blood therethrough outsidethe patient's body and back into the patient. Such functionality mayallow for the monitoring of blood volume and performing hemofiltration.

In at least some embodiments, the catheter 1 can include one or moreradiopaque markers (not shown) configured to be visible using an imagingtechnique such as fluoroscopy. The one or more radiopaque markers can beon the catheter's shaft 7 at or near one or more features along theshaft 7, such as any or all of the inlet openings or any or all of therestrictors 2 a, 2 b. The one or more radiopaque markers may thusfacilitate proper positioning of the shaft 7 and/or features thereonwithin a vein. For example, prior to activation of the catheter'srestrictor(s) 2 a, 2 b, the position of the restrictor(s) 2 a, 2 bwithin the vein 3 can be verified by visualizing the one or moreradiopaque markers using an imaging system.

The first and second restrictors 2 a, 2 b are discussed with respect toFIG. 1 above as being balloons configured to inflate and deflate, butthe first and second restrictors 2 a, 2 b can have other configurations.For example, the first and second restrictors 2 a, 2 b can each includea stent configured to expand (corresponding to an activatedconfiguration) and constrict (corresponding to a relaxed configuration).The expandable/constrictable stents can have a variety ofconfigurations, as will be appreciated by a person skilled in the art.

FIG. 2 illustrates another embodiment of a catheter 100 that includes atleast one restrictor (not shown in FIG. 2 for clarity of illustration).The catheter 100 of FIG. 2 can generally be configured and used similarto that discussed above regarding the catheter 1 of FIG. 1 , e.g.,include a shaft 102, a soft, distally-tapering atraumatic tip 104, adischarge opening 106, a proximal inlet opening 108, an impeller 110, adrive shaft 112 extending proximally to a motor (not shown), and adistal inlet opening 114. The motor in this illustrated embodiment isexternal, similar to the embodiment discussed above regarding thecatheter 1 of FIG. 1 . The proximal inlet opening 108 in thisillustrated embodiment is in the form of two opposed ovular openingsformed through a sidewall of the shaft 102. The distal inlet opening 114in this illustrated embodiment is in the form of two opposed ovularopenings formed through a sidewall of the atraumatic tip 104 distal tothe shaft 102 (one of the openings is obscured in FIG. 2 ). The catheter100 can include a bearing 116 just proximal to the impeller 110, whichmay help stabilize the impeller 110 within the shaft 102.

FIG. 3 through FIG. 6 illustrate another embodiment of a catheter 200that includes at least one restrictor (not shown in FIG. 3 through FIG.6 for clarity of illustration). The catheter 200 of FIG. 3 through FIG.6 can generally be configured and used similar to that discussed aboveregarding the catheter 1 of FIG. 1 , e.g., include a shaft 202, a soft,distally-tapering atraumatic tip 204, a discharge opening 206, aproximal inlet opening 208, an impeller 210, a motor 212, a drive shaft214 extending between the impeller 210 and the motor 212, and a distalinlet opening 216. The motor 212 in this illustrated embodiment is anon-board motor configured to be implanted with the catheter 200. Similarto the catheter 100 of FIG. 2 , the proximal inlet opening 208 in thisillustrated embodiment is in the form of two opposed ovular openingsformed through a sidewall of the shaft 202, and the distal inlet opening216 in this illustrated embodiment is in the form of two opposed ovularopenings formed through a sidewall of the atraumatic tip 204 distal tothe shaft 202 (one of the openings is obscured in FIG. 3 and FIG. 4 ).

FIG. 7 through FIG. 9 illustrate another embodiment of a catheter 300that includes at least one restrictor 318, which in this illustratedembodiment includes only one restrictor 318 that is located distal to animpeller 310. The catheter 300 of FIG. 7 through FIG. 9 can generally beconfigured and used similar to that discussed above regarding thecatheter 200 of FIG. 3 through FIG. 6 , e.g., include a shaft 302, asoft, distally-tapering atraumatic tip 304, a discharge opening 306, aproximal inlet opening 308, the impeller 310, an on-board motor 312, adrive shaft 314 extending between the impeller 310 and the motor 312,and a distal inlet opening 316. The shaft 302 includes multiple lumensextending therethrough, including a central lumen 320 for the impeller310 and the motor 312 and an inflation lumen 322 for inflation/deflationof the restrictor 318, which in this illustrated embodiment includes aballoon. FIG. 7 through FIG. 9 show the restrictor 318 in an activatedconfiguration, which in this illustrated embodiment is an inflatedconfiguration.

In at least some embodiments, a catheter including restrictors caninclude a flexible membrane to which the restrictors are appended andwhich enables fluid (e.g., blood flow) to bypass a low pressure zonedefined between the restrictors.

FIG. 10 illustrates one embodiment of an indwelling catheter system 10that can include a flexible membrane 28 and at least one restrictor 22,24, which are in the form of balloons in this illustrated embodiment. Asillustrated, the indwelling catheter system 10 includes an introducersheath 30 used to deploy a catheter 20 having a generally elongatetubular shape, with a circular or ovular cross-sectional geometry. Theindwelling catheter system 10 can include proximal end 10 p, which canbe configured to be placed outside of a patient's body, and distal end10 d, which can be configured for placement within a patient's vein.

The catheter 20 can have a single suction lumen 48 (see FIG. 24 and FIG.25 ) for communicating fluid out of the vein to an external pump, theflexible membrane 28 (which is tubular in this illustrated embodiment),and first and second restrictors 22, 24, which are attached to themembrane 28 and surround the membrane 28 and catheter 20. The flexiblemembrane 28 can be assembled to the catheter 20 (e.g., to the shaftthereof) in any of a number of ways to enable the flexible membrane 28to form an ovoid or a kidney shape upon expansion of the flexiblemembrane 28 (as a result of activating the restrictors 22, 24) so thatfluid can be transported from a position within the vein proximal to thefirst restrictor 22, through the low pressure zone within the vein, andto discharge the fluid at a point distal to the second restrictor 24.The flexible membrane 28 can be attached, e.g., bonded or welded, arounda partial portion (such as a non-zero portion that is less than 360° ofthe catheter shaft's circumference 50) or full portion (360° around thecatheter shaft's circumference 50) of the circumference 50 of thecatheter's shaft, such as in a range of about 10° to 360° of the shaft'scircumference 50.

FIG. 11 and FIG. 12 illustrate the flexible membrane 28 attached to apartial portion around the catheter shaft circumference 50. At least oneinflation port 56 is in fluid communication with an inflation lumen(control lumen 42 discussed further below) for inflating the firstrestrictor 22 and is disposed on a surface of the flexible membrane 28and will be underneath the first restrictor 22 attached thereto, asdiscussed below. A second inflation port (not shown) is in fluidcommunication with at least one inflation lumen (control lumen 44discussed further below) for inflating the second restrictor 24 and isdisposed on a surface of the flexible membrane 28 and will be underneaththe second restrictor 22 attached thereto, as discussed below. As shownin FIG. 12 , which has a portion of the flexible membrane 28 removed forclarity of illustration, at least one suction port 26 is extendingthrough an external surface of the catheter 20 such that it is in fluidcommunication with a suction lumen 48.

Following attachment of the flexible membrane 28 to the catheter 20, therestrictors 22, 24 can be attached to the catheter 20. As shown in FIG.13 , the first restrictor 22 can be bonded or welded to an outer surfaceof the flexible membrane 28 over the inflation port 56 so that the firstrestrictor 22 surrounds the outer circumference 52, 54, of the catheter20 and the flexible membrane 28. As shown in FIG. 14 , edges of thefirst restrictor 22 can be flattened to extend beyond the collapsedballoon and bonded to the flexible membrane 28. The second restrictor 24can be attached to the catheter 20 similar to the first restrictor'sattachment to the catheter 20. In an alternate embodiment, as shown inFIG. 15 , a restrictor 22′ has at least one edge 52′ thereof foldedunder and bonded beneath the collapsible tube of the restrictor 22′. Oneor both of the first and second restrictors 22, 24 can be attached tothe catheter 20 similar to the attachment of the restrictor 22′ of FIG.15 .

FIG. 15 through FIG. 18 illustrate one embodiment of a method formanufacturing a torus-shaped restriction member 502 configured to beattached to a catheter shaft as discussed herein. As shown in FIG. 16 ,a pattern 500 is formed by a process such as blow molding or dipmolding. For example, a slope of the mold pattern can be formed in acontinuous shape without sharp corners or directional reversion. Asshown in FIG. 17 , after the restriction member 502 is formed using thepattern 500, it is assembled onto a collapsible sleeve 510. During theassembly, two legs 504, 506 of the restriction member 502 are pushedtowards each other and bonded together. The restriction member 502maintains an opening 508 between the legs 504, 506 to enable theformation or positioning of an inflation port in the catheter that willbe used to inflate the restriction member 502. As shown in FIG. 18 ,after the legs 504, 506 are brought together, as explained above, alower section of the restriction member 502 is inverted inward. Thecurvature of the restriction member 502 is maintained in the oppositedirection thereby maintaining material continuity to form therestriction member 502, as illustrated.

The suction lumen 48 can accommodate the flow of fluid from the vein inwhich the catheter 20 is implanted to a pump external to the patient,when deployed, and the membrane 28 can enable fluid returned from thepump to bypass the portion of the vein occluded by the restrictors 22,24. As shown in FIG. 19 , FIG. 20 , FIG. 24 , and FIG. 25 , the suctionlumen 48 can communicate with the suction port 26, formed in an outerwall of catheter 20, and can extend to a proximal end of the catheter20. The proximal end of the catheter 20 can include a hub 34 whichcommunicates with discharge tubing (not shown) coupled to the pumpexternal to the patient (not shown) to communicate fluid withdrawn fromwithin the low pressure zone between the restrictors 22, 24 through thesuction lumen 48 of the catheter 20. Fluid present in the vein in whichthe catheter 20 is implanted, and between the deployed restrictors 22,24 of the catheter 20, is drawn from the vein into the suction port 26and into the suction lumen 48 of catheter 20 so that it can becommunicated to the external pump (not shown) via the suction lumen 48and the discharge tubing.

The tubing extending out of the pump (not shown) to return fluid to thecatheter system 10 can be coupled to the sheath 30 at a discharge port36 (see FIG. 10 , FIG. 21 , FIG. 22 , and FIG. 23 ). Fluid returned fromthe pump will enter the discharge port 36 and be discharged within thevein external to the catheter 20. The pump can facilitate fluid movementfrom the catheter 20 through the suction lumen 48 and into the dischargetubing through which it is communicated to the pump. The discharge port36 can be configured to connect to an end of the drainage tubing havingits other end in fluid communication with the pump. The discharge port36 can, as shown, include surface features formed thereon and extendingaround to facilitate its connection to the discharge tubing.

As shown in FIG. 10 , FIG. 11 , FIG. 19 , and FIG. 20 , the firstrestrictor 22 can be downstream of (e.g., distal to) a proximal opening28 p of the membrane 28, and a distal opening 28 d of the membrane 28can be downstream of second restrictor 24. Thus, when the first andsecond restrictors 22, 24 are activated or deployed to fully occlude thevein, the lumen of the membrane 28 can provide a bypass route for fluid(e.g., blood) returning from the external pump or otherwise flowingdownstream within the vein external to catheter 20. In other words, eventhough the vein is occluded by the restrictors 22, 24, blood and otherfluid can flow through the lumen of the membrane 28 to flow from aposition upstream of (e.g., proximal to) the proximal restrictor 22 to aposition downstream of the distal restrictor 24. Although the catheter20 and the flexible membrane 28 are illustrated to be oriented in aside-by-side relationship with respect to one another, they can beoriented in any other suitable manner, including having one memberdisposed within the other member. Also, the catheter 20 can have anynumber of additional lumens, which can function, for example, as controllumens to facilitate activation of the restrictors 22, 24 and/or tosense pressure at various locations within the vein in which thecatheter 20 is disposed.

The catheter 20 can include a distal atraumatic tip 12 that canfacilitate placement of the catheter 20 into the vein of a patient. Thedistal atraumatic tip 12 can have an aperture such that the tip 12 has alumen extending therethrough. The lumen of the tip 12 can be configuredto allow passage of a guide wire through the tip 12. The catheter 20,including the flexible membrane 28 and the restrictors 22, 24, can beadvanced over the guide wire to be deployed from the sheath 30. Thelumen and the aperture can be sized to accommodate a standard guide wireof size such as about 0.014″, about 0.018″, about 0.035″, or about0.038″. In addition to or instead of the catheter 20 including thedistal atraumatic tip 12, the sheath 30 can include a distal atraumatictip to facilitate advancement of the sheath 30 having the catheter 20disposed therein to a location where the catheter 20 is to be releasedfrom (e.g., advanced distally out of) the sheath 30. The sheath's distalatraumatic tip can include a lumen to allow passage of a guide wirethrough the tip, as discussed above.

FIG. 20 shows the catheter 20 can include one or more radiopaque markers21 configured to be visible using an imaging technique such asfluoroscopy. As also shown in FIG. 20 , the catheter 20 can include oneor more sensors 23, which in this illustrated embodiment includes anoptic pressure transducer, located between the restrictors 22, 24 andhence within a low pressure zone created between. The pressuretransducer 23 is configured to continually monitor pressure within thelow-pressure zone so pump function can be adjusted if necessary to keepthe pressure at a desired level (in a desired range of about 2 to 5mmHg, etc.) and at the location of the discharge lumen so internaljugular vein pressure can be monitored. The pressure transducer 23 isalso configured to provide CVP measurements when the restrictors 22, 24are deflated.

As shown in FIG. 22 , the catheter system 10 can include an eyelet 25configured to facilitate securement of the system 10 to a patient duringuse. For example, the eyelet 25 can be secured by a suture to thepatient's skin. The catheter shaft can be locked in position relative tothe sheath 30 using, for example, a Tuohy Borst valve, such that thecatheter 20 can be secured to the patient during use via the sheath 30.The eyelet 25 may thus be secured to the patient after the catheter 20has been advanced through the sheath 30 to be in a desired positionwithin the patient to help ensure that the system 10 is secured to thepatient with the catheter 20 in its desired position.

As shown in FIG. 10 , FIG. 12 , and FIG. 23 , the sheath 30 can includea plurality of ports 32 a, 32 b, 32 c in fluid communication withrespective ones of a plurality of control lumens 42, 44, 46 within thecatheter 20. As shown in FIG. 24 through FIG. 26 , the first and secondports 32 a, 32 b respectively communicate with the first and secondcontrol lumens 42, 44, which can be configured to deliver fluid to thefirst and the second restrictors 22, 24, respectively, to control theactivation and deactivation of the restrictors 22, 24. The third port 32c can communicate with the third control lumen 46, which can communicatewith an opening in the catheter 20 for purposes of sensing a pressurewithin the vein, as discussed above. The third control lumen 36 includesone or more pressure sensors in this illustrated embodiment, but any oneor more of the control lumens 42, 44, 46 can include one or morepressure sensors, to be used for sensing pressure at various locationsalong the vein in which the catheter 20 is implanted, such as betweenthe proximal and distal restrictors 22, 24 and upstream of the proximalrestrictor 22.

FIG. 25 shows the suction lumen 48 is internal to the catheter 20 andthe flexible membrane 28 that is external to the catheter 20 and isoriented in a side-by-side arrangement with respect to the catheter 20.The control lumens 42, 44, 46 can be disposed within the catheter 20,such as within the wall of the catheter 20, as shown. As indicatedabove, the cross-sectional arrangement of catheter 20 can take variousforms, and the relative positioning of the suction lumen 48 and thecontrol lumens 42, 44, 46 can vary. More or fewer suction lumens 48 andcontrol lumens 42, 44, 46 can be provided in the catheter 20. Forexample, one or more additional control lumens can accommodate a varietyof non-pressure sensors, as discussed above.

Sizes of the catheter 20, the sheath 30, and the flexible membrane 28can vary depending upon the catheter system's intended uses. Generally,the catheter 20 can have a length in the range of about 25 to 40 cm. Inaddition, the diameter can also vary, but suitable catheters willtypically be in the range of about 8 to 18 Fr. Other catheters describedherein can have a similar size, e.g., a length in the range of about 25to 40 cm and a diameter in the range of about 8 to 18 Fr. The sheath 30can have a length in the range of about 10 to 25 cm, can have aninternal diameter in the range of about 2.5 to 5.5 mm, and can have anexternal diameter in the range of about 3 to 6 mm. In one embodiment,the catheter 20 can have a diameter of about 8 Fr and the sheath 30 canhave a diameter of about 11 Fr. The flexible membrane 28 can have alength in the range of about 50 to 150 mm. A distance between the distalend of the sheath 30 and the proximal end of the flexible membrane 28can be up to about 100 mm. The diameter of the control lumens 42, 44, 46can vary depending upon the requirements of a given application. Thesuction lumen 48 can have a diameter in the range of about 1 to 4 mm,while pressure inflation lumens can have a diameter in the range ofabout 0.1 to 1 mm.

FIG. 27 through FIG. 29 illustrate one example of the catheter 20implanted within a patient, in particular within a jugular vein 80 ofthe patient. FIG. 28 also illustrates a location of the low pressurezone and illustrates fluid flow through the catheter 20 as indicated bytwo sets of arrows into and one set of arrows out of the catheter 20.FIG. 29 also illustrates one embodiment of a pump 27, a peristaltic pump(such as a peristaltic blood pump motor model 48 VDC, Head model 520RL2,sold under the trademark DRIVESURE from Watson Marlow), configured topump fluid in and out of the catheter system 10 via the ports 32 a, 34.As shown, the first restrictor 22, which in this illustrated embodimentis positioned at a region of the catheter 20 that is proximal to thesuction port 26 and that marks the proximal or upstream boundary of thelow pressure zone, can be positioned proximal to (upstream of) a pointat which the patient's subclavian vein 82 enters the jugular vein 80.The second restrictor 24, which in this illustrated embodiment ispositioned distally of the first restrictor 22 and between the suctionport 26 and the distal end of the catheter 20, can be positioned distalto (downstream of) the point at which the subclavian vein 82 enters thejugular vein 80, and the second restrictor 24 can be in the patient'sinnominate vein 84. Alternatively, the catheter 20 can treat bothlymphatic ducts by placing the first restrictor 22 proximal to (upstreamof) the point at which the subclavian vein 82 enters the jugular vein 80and placing the second restrictor 24 distal (downstream of) to the pointat which both of the patient's innominate veins enters the subclavianvein 82. Alternatively, the second restrictor 24 can be positioned inthe subclavian vein 82.

The catheter 20 can be positioned with the jugular vein 80 as shown inFIG. 27 and FIG. 28 in any of a variety of ways. For example, thepositioning can be conducted using a 12 Fr sheath 30 to puncture thevenous wall. The sheath 30 can be advanced into the vein 80 with thecatheter 20, the flexible membrane 28, and the restrictors 22, 24collapsed and contained therein. After insertion of the sheath 30, thecatheter 20 along with the flexible membrane 28 and the restrictors 22,24, can be advanced through the distal tip of the sheath 30 andpositioned downstream of the sheath 30. Alternatively, the sheath 30 canbe introduced first, and then the catheter 20 can be introduced by beingadvanced through the sheath 30. Regardless of whether the sheath 30 andthe catheter 20 are introduced sequentially or simultaneously, thecatheter 20 can be configured to be removed from the sheath 30 at anytime. If at any time throughout a procedure there might be a questionwith regards to the integrity of the catheter 20, the catheter 20 beingremovable with the sheath 30 remaining in place within the patientallows the catheter 20 to be replaced with a new one introduced into thesheath 30 or for the catheter 20 to be reintroduced into the sheath 30if the catheter's integrity is deemed acceptable.

The distal restrictor 24, when activated, isolates the incoming bloodflow from the subclavian and jugular veins 82, 80 from the blood flow ofthe innominate vein 84 and ensures that all incoming blood is directedto the pump 27. The proximal restrictor 22, when activated, isolates theblood flow from the jugular vein 80 and ensures that all blood flow froma position upstream of the proximal restrictor 22 is transported throughthe flexible membrane 28. The pump is activated to maintain the jugularand innominate vein pressure and thus the nominal blood flow. Theproximal restrictor 22, when activated, directs the blood flow from thejugular vein 80 and from the discharge port 36 within the sheath 30 downto the innominate vein 84. Actuation of the pump helps to create a lowpressure zone in the vicinity of the junction of the jugular vein 80 andthe subclavian vein 82 by withdrawing fluid in this region,recirculating it through the pump, and discharging the fluid upstream ofthis region through the sheath 30. Because the outflow of the thoracicand lymphatic ducts is located in this region, the lower pressure willfacilitate drainage of lymphatic fluid.

The catheter 20 can be implanted in the jugular vein 80 as shown in FIG.27 and FIG. 28 in any of a variety of ways. FIG. 30 through FIG. 32illustrate one embodiment of implanting the catheter 20 can be implantedin the jugular vein 80. The catheter 20 can be similarly implanted inanother vein, and other catheters described herein can be implanted in avein similar to that discussed with respect to FIG. 30 through FIG. 32 .

FIG. 30 and FIG. 31 illustrate the indwelling catheter system 10 (only adistal portion thereof is shown in FIG. 30 ) in an initial configurationin which the catheter 20 is disposed within the sheath 30 in acompressed configuration. In the initial configuration, the sheath 30can have the catheter shaft 20 positioned therein, encircled by acompressed flexible membrane 28 further surrounded by compressedrestriction members 22, 24.

A distal portion of the indwelling catheter system 10, e.g., a distalportion of the sheath 30, in the initial configuration can be insertedinto the jugular vein 80 of the patient, which is the right internaljugular vein in this illustrated embodiment. A proximal portion of theindwelling catheter system 10, e.g., a portion including the ports 32,34, 36, can remain outside the body of the patient to facilitate accessto the ports 32, 34, 36. With the distal portion of the catheter system10 at the target site (e.g., within the vein in which the catheter 20 isto be implanted), the catheter 20 can be advanced out of the sheath 30,as shown in FIG. 32 , such that a proximal portion thereof is positionedwithin the jugular vein 80 and a distal portion thereof is positionedwithin the SVC 84. The suction port 26 disposed between the first andsecond restriction members 22, 24 enables suction of blood depositedwithin the low pressure zone from the subclavian vein 82 and from theinnominate vein 84. Such arrangement enables drainage of both thepatient's right lymphatic duct and thoracic duct. After positioning ofthe catheter 20 within the patient, the first and second restrictors 22,24 can be expanded, e.g., moved from their relaxed configuration totheir activated configuration, as shown in FIG. 27 and FIG. 28 . Theexpansion of the restrictors 22, 24 also expands the flexible membrane28, e.g., moved the flexible membrane 28 from a relaxed configuration toan activated configuration. As mentioned above, the restrictors 22, 24can be expanded simultaneously or sequentially. As mentioned above, theexpansion of the restrictors 22, 24 isolates a portion of the vein 80 inwhich the catheter 20 is deployed from a surrounding area, and, thus, anarea (e.g., a low pressure zone) proximate to the thoracic duct isisolated and fluid can be removed via the suction port 26 positioned onthe catheter 20 located within the isolated area.

The catheter system 10 discussed above is configured to pump blood outof a patient's body and back into the body. A catheter system caninstead include an impeller, such as in the catheter embodiments of FIG.1 through FIG. 6 , such that blood need not be pumped out of and backinto a patient's body and features of the catheter system 10 relatedthereto need not be included (e.g., a pump, a discharge port, andrelated tubing need not be included). The catheter system including animpeller can otherwise be similar to the catheter system 10, e.g.,include a flexible membrane, include a sheath, etc.

The catheters described herein can be used in a variety of surgicalmethods, including surgical methods for treating pulmonary edema. Themethod can include verifying a location of the patient's thoracic ductand/or the patient's lymphatic duct, which can help a surgeon and/orother medical professional involved in performing a surgical procedurethat includes implanting the catheter verify that the restrictor(s) ofthe catheter are implanted in the correct location within the patient.The verification can be performed in any of a variety of ways, as willbe appreciated by a person skilled in the art, such as by using animaging technique such as echo or fluoroscopy. In an exemplaryembodiment, the verification can include advancing a set of pig tailedwires into the patient's subclavian or jugular veins and advanced towarda junction of the jugular and subclavian veins. Once one of the pigtailed wires enters the lymphatic duct or the thoracic duct, that one ofthe pig tailed wires can open itself inside the duct it entered, e.g.,due to a default expanded configuration of the wire. The pig tailedwires can include, for example, a default expanded circle size of 4 cm.The location of the entered duct can be verified using an imagingtechnique that visualizes the expanded wire therein.

The verification can occur after the implantation of the catheter suchthat the implanted location of the catheter can be determined in view ofthe verification and adjusted if need be in view of the verification.Additionally or alternatively, the verification can be performed priorto the implantation of the catheter. Similarly, the verification can beperformed prior to and/or after the restrictor(s) are moved from therelaxed configuration to the activated configuration to verify theposition(s) of the restrictor(s), and the verification can be performedprior to and/or after one or more sensors are implanted to verify thatthe sensor(s) are desirably positioned. As discussed above, thesensor(s) in some embodiments are not implanted and are instead locatedoutside the patient's body, and/or at least one sensor is implanted andat least one sensor is located outside the patient's body. Variousembodiments of positioning tubes such as catheters is further describedin U.S. Patent Publication No. 2015/0343136, incorporated by reference.

With the catheter implanted, the restrictor(s) in the activatedconfiguration, and, if being used in the system, the sensor(s)positioned, fluid flow can be controlled with the pump. The control cangenerally occur as described above. In at least some embodiments,controlling the pump can include continuously running the pump. In atleast some embodiments, controlling the pump can include periodicallyrunning the pump. In periodically running the pump, the pump can defaultto an idle state in which the pump is not pumping fluid. For example, inresponse to receipt of a user input requesting pumping, e.g., input by auser to an I/O device in electronic communication with the pump via acontroller, input wirelessly to the pump, etc., the pump can be actuatedso as to run and pump fluid. The pump can continue pumping untiloccurrence of a stop condition. Examples of the stop condition include apredetermined amount of time passing after the pump starts running and asecond user input being received that requests pumping to stop. Inresponse to the stop condition occurring, the pump can be actuated toreturn to its idle state. For another example, in response to sensing aparticular parameter value (e.g., a particular pressure value, etc.)with one or more sensors, the pump can be actuated so as to run and pumpfluid or the pump can be stopped so as to stop pumping fluid. Theparameter can continue being measured with the one or more sensors,thereby allowing the pump to be controlled in real time in response tomeasured values.

FIG. 33 illustrates one example of another catheter system 701 havingdistal, first restrictor 719, and a second restrictor 739. The cathetersystem 701 includes an indwelling catheter 727, which can be in the formof a disposable catheter unit, and a mechanical fixator part which canbe enclosed in a sterile package prior to use. Some components of thesystem, such as a console having a controller, a display configured todisplay information and receive user input, cables, etc., can bereusable components. The catheter system 701 includes a catheter shaft719 configured to be at partially implanted within a blood vessel of apatient; an impeller assembly 711 disposed at a distal portion 722 ofthe catheter shaft 719; a flexible membrane 715 connected to the distalportion 722 of the catheter shaft 719 (e.g., optionally to the impellerassembly); and the selectively deployable restrictor 715 attached to thedistal portion 722 via the flexible membrane 715, such that deploymentof the restrictor 719 causes the flexible membrane 715 to assume atapered configuration, defining a tapered lumen extending through therestrictor, the flexible membrane, and at least a portion of theimpeller assembly. The system 701 preferably further includes a proximalassembly 735 including a sheath 723 and a proximal balloon 739, as wellas a centralizer 731 defining a portion of the main catheter 727.

As shown in FIG. 33 , the system includes a main catheter with a distalassembly, a centralizer member, and a proximal assembly. The maincatheter includes a propulsion system including at least an impeller anda motor (which can be disposed at least in part outside of the patient'sbody), a distal restriction member in the form of a distal balloon, anda distal atraumatic tip.

The centralizer member can be in the form of a housing encompassing asealing component and at least a part of a motor. The housing isconfigured to keep the assemblies of the system aligned, while allowingan axial movement of the assemblies. The system includes a motorconfigured to move a drive shaft (e.g., a torque coiled drive shaft or ashaft having another configuration) inside a multi-lumen sleeve. Inaddition, the motor is configured to cause the distal balloon toinflate. One or more components of the motor can be disposed within thecentralizer member.

The motor can be, for example, an extracorporeal motor configured todeliver the driving force to the impeller through the drive shaft. Themotor can have a shaft with a channel extending therethrough to allow aguide wire to be inserted through the shaft. Additionally oralternatively, a mechanism configured to facilitate insertion andremoval of the guide wire can be utilized. The catheter can include atleast one inflation lumen through which an inflation fluid (e.g., air,liquid, etc.) can be introduced to inflate/deflate the restrictors. Therestrictors can be inflate/deflate using separate components. Thecatheter can also include a suction lumen, and any other lumens.

The proximal assembly includes a proximal assembly tube having aproximal restriction member in the form of a proximal balloon at adistal end thereof. The proximal assembly is configured to regulateblood flow in the jugular vein. The proximal assembly can include aregulation mechanism configured to adjust the central venous pressure(CVP).

FIG. 33 through FIG. 35 show a distal end of the drive shaft is attachedto an impeller assembly that includes the impeller and a housing or cagedisposed around the impeller and having openings (e.g., radial openings)that allow blood to flow therefrom. A conical membrane is attached tothe cage and at least partially wraps around the distal balloon.

FIG. 33 shows the catheter system 701 having a single selectivelydeployable restrictor 719 and a flexible membrane 715 and disposed inthe left internal jugular vein to decrease the pressures distally of therestrictor 719. The system 701 includes an impeller assembly 711disposed at a distal portion 722 of the catheter shaft 719. The flexiblemembrane 715 is connected to the distal portion 722 of the cathetershaft 719 (e.g., optionally to the impeller assembly). The sheath 723includes components or fixtures configured to removably couple thecatheter inside a patient. The sheath also has components operating as acover sheath during deployment. As shown in FIG. 33 , the drive shaftextends at least partially through a proximal assembly tube, and thecentralizer encompasses at least a portion of the proximal assembly. Thesheath is disposed so as to encompass at least a portion of the proximalassembly such that the proximal balloon is disposed distally to thedistal end of the sheath.

FIG. 34 illustrates a portion of the proximal assembly.

FIG. 35 shows the distal assembly 722 that includes the impeller 712that is driven by the motor to which it is coupled via the drive shaft718.

FIG. 36 is a perspective view of the distal assembly 722 of the cathetersystem 701.

FIG. 37 is a back view back view of the distal assembly 722.

FIG. 38 shows a proximal restrictor 739 that regulates jugular flow andpressure.

FIG. 39 is cross-section through a portion of the catheter.

FIG. 40 shows an impeller 712 for a catheter system 701 of thedisclosure.

FIG. 41 is a side view of an impeller housing for the impeller assembly711.

FIG. 42 is a perspective view of the impeller housing.

FIG. 43 shows the multi-strut support ring.

FIG. 44 is a detail view of the conical membrane 415.

FIG. 45 shows the flexible, atraumatic tip 707.

FIG. 46 illustrates the catheter system 701 in use in a method fortreating edema with a straight multi-lumen configuration implanted in apatient's body.

FIG. 47 shows a similar catheter system, a closely related embodiment,implanted in a patient's body, the system having a bent or kink betweenthe proximal and distal restrictors.

As shown in FIG. 46 , the catheter system for treating edema includes anindwelling catheter configured for placement within a vein of a patient.The indwelling catheter includes a drive shaft having a lumen extendingtherethrough, wherein a distal portion of the drive shaft is operativelycoupled to an impeller. The catheter also includes a first selectivelydeployable restriction member adjacent and proximal to the impeller. Asshown, the first restriction member, which can be in the form of adistal balloon, has a membrane operatively coupled thereto andconfigured to direct fluid from an upstream side of the firstrestriction member to the impeller. The membrane can be a conicalmembrane, though it can have any suitable configuration. The catheteralso includes a second selectively deployable restriction member (e.g.,in the form of a proximal balloon) proximal to the first restrictionmember. The second restriction member is operatively coupled to a flowregulation component configured to direct a controlled volume of fluidfrom an upstream side of the second restriction member to a downstreamside of the second restriction member. The jugular flow enters throughopenings formed in the flow regulation component and follows to the gapbetween the main catheter and an inner lumen of the proximal assembly.In this way, as shown by arrows in FIG. 46 , blood flows from theupstream side of the second restriction member, enters a portion of thecatheter between the first and second restriction members, and isdirected to the downstream side of the second restriction member. Thecomponents through which blood flows have a common lumen extendingtherethrough. The impeller is rotated via the draft shaft by a motor.

In FIG. 46 , the first and second restriction members are shown in thedeployed configuration. The first restriction member can be, forexample, doughnut shaped and it can allow for a maximum free flow offluid and for minimal resistance. As shown in FIG. 46 , the first andsecond restriction members can be implanted so as to create a lowpressure zone between. In use, the system is operated so as to regulatea fluid flow in the low pressure zone. Transporting the fluid throughthe localized low pressure zone via can maintain a constant pressurewithin the low pressure zone. The second (proximal) restriction memberis configured to regulate jugular flow and it is configured to restrictblood flow. The conical membrane can allow for diffusing the fluid flowfrom the isolated zone to the impeller. The geometrical shape of themembrane allows delivering the flow smoothly to the impeller andtherefore reduces resistance to the flow. The system in FIG. 47 can beconfigured similar to that in FIG. 46 .

Some examples of various components of the catheter system and examplesof dimensions of the components are discussed for the proximal assemblyand distal assembly.

FIG. 38 shows a restrictor that regulates Jugular flow and pressure byhaving 1-4 opening sections at its proximal side and allow for thejugular flow (e.g., 300-500 ml/min) to enter through the sections and inthe gap between the main catheter and an inner lumen of the proximalassembly. An example of a section dimension range: 1×5 mm.

FIG. 39 is cross-section through a portion of the catheter showing astructure that supports and holds the proximal balloon.

FIG. 40 shows the Impeller. The impeller functions as the drivingmechanism of the blood. It pumps blood from the center portion of thesystem and drives it distally and outward towards the vessel perimeter.The impeller may include more than one (e.g., 2-4, or greater than 4)blades. The rotation speed should be <25000 @ 11/min in order to reducehemolysis risk. The impeller shaft contains a lumen in which a guidewire can pass through.

FIG. 41 is a side view of the cage, or impeller housing. The dimensionsfollow the impeller dimensions with a minimal gap between them (0.05-0.2mm)

FIG. 41 is a perspective view of the cage. Preferably, the cage caninclude an extension to support the catheter while keeping the suctionlumen fully open.

FIG. 44 is a detail view of the conical membrane. The conical membranecan allow for diffusing the flow from the isolated zone to the impeller.The geometrical shape will deliver the flow smoothly to the impeller andtherefore reduce resistance to flow. The conical length (LI) shall be2-10 mm.

FIG. 43 shows the multi-strut support ring. This ring holds the driveshaft centralized and keep the impeller in place.

FIG. 45 shows the flexible, atraumatic tip. The tip allows a gentleinsertion to the vessel and allows for a guide wire insertion. The tipis connected to the cage at its proximal end. In some embodiments, thetip has a length of about 0.5-15 mm.

It should be appreciated that the components of the system are shown byway of example only, and that the dimensions of the components are shownby way of example only.

The catheter system also includes a controller that can be configured tobe in electronic communication with at least one pressure sensor (notshown). A person skilled in the art will appreciate that a variety ofsuitable sensors can be used for monitoring pressure, such as centralvenous pressure (CVP) or other fluid pressure sensors, and bloodpressure sensors. The at least one pressure sensor can be implanted inthe patient as part of the impeller, implanted in the patient as aseparate component from the impeller, or the at least one pressuresensor can be located external to the patient, such as by being on askin surface thereof. If not already a part of the impeller so as to bein electronic communication therewith, the at least one pressure sensorcan be configured to be in electronic communication with the impellerover a communication line such as a wired line or a wireless line.

In an exemplary embodiment, three pressure sensors can be implanted inthe patient. One of the pressure sensors can be implanted between thefirst and second restriction members as to be in the low pressure zone.Another pressure sensor can be implanted in the vein proximal to thesecond restriction member, and another pressure sensor can be implantedin the vein distal to the first restriction member, so as to be in thehigher pressure zones. The sensors can allow a pressure differential tobe determined between the low pressure zone and the higher pressurezone. In other embodiments, another number of pressure sensors can beimplanted in the patient (e.g., one, three, four etc.) and/or thepressure sensor(s) can be implanted at other locations.

The catheter can include at least one lumen (not shown) configured tofacilitate use of the pressure sensor(s), for example to facilitateplacement of the pressure sensor(s) and/or to be filled with a fluidsuch as saline to allow for external pressure measurement.

In addition to or instead of the one or more pressure sensors, thecontroller can be configured to be in electronic communication with atleast one other type of sensor (not shown) configured to sense aparameter other than pressure. Examples of sensors that can be used tomeasure a parameter other than pressure include radio frequencytransmitters and receivers, fluid sensors, bioimpedance sensors, heartrate sensors, breathing sensors, activity sensors, and optical sensors.Examples of the measured parameter include fluid amount (e.g., asmeasured by a fluid sensor, such as a fluid sensor placed in a lung tosense fluid amount in the lung), bioimpedance (e.g., as measured by abioimpedance sensor), heart rate (e.g., as measured by a heart ratesensor), breathing rate (e.g., as measured by a breathing sensor),patient activity level (e.g., as measured by an activity sensor), andorgan dimension (e.g., as measured by an optical sensor). The sensor canbe implanted in the patient as part of the pump, implanted in thepatient as a separate component from the pump (e.g., implanted in aninterstitial space around a lung, implanted at a junction of a rightsubclavian vein of a patient and an internal jugular vein of thepatient, implanted at a junction of a left subclavian vein of a patientand an internal jugular vein of the patient, etc.), or the sensor can belocated external to the patient, such as by being on a skin surfacethereof.

The controller can include any type of microprocessor or centralprocessing unit (CPU), including programmable general-purpose orspecial-purpose microprocessors and/or any one of a variety ofproprietary or commercially available single or multi-processor systems.The controller can be a component of a control system that includes anynumber of additional components, such as a memory configured to canprovide temporary storage and/or non-volatile storage; a bus system; anetwork interface configured to enable the control system to communicatewith other devices, e.g., other control systems, over a network; and aninput/output (I/O) interface configured to connect the control systemwith other electronic equipment such as I/O devices (e.g., a keyboard, amouse, a touchscreen, a monitor, etc.) configured to receive an inputfrom a user. The controller can be configured to receive user inputthereto to control any of a variety of aspects related to the catheter,such as speed of the motor and ideal range of pressure for the lowpressure zone.

In use, the catheter system can be attached to a patient near anincision point. One or more electronic cables can be connected to amultiuse console that includes a motor controller, a pressure sensoramplifier, firmware with data acquisition system, power supply, touchscreen monitor, and any other suitable components.

FIG. 62 diagrams steps of a method of implanting a catheter system, toimplant the system, a sterile catheter kit is shipped to the clinicalsite in its open state, in which a distal portion of a distal assemblyis unsheathed (s1). Prior to an implanting procedure, a user (e.g., aphysician assistant) can insert the distal assembly into a sheath lumen,e.g., by using a handle Tuhy (s2). The catheter is then inserted by thephysician over a guide wire into the jugular vein (e.g., posteriorapproach) (s3). Once it is confirmed (using, e.g., an ultrasoundtechnique) that the catheter is located in the jugular vein, theoperator can un-sheath the distal unit in two consecutive steps. First,the distal balloon can be un-sheathed and positioned in the innominatevein just past the subclavian drainage (s5, s6). Second, the proximalballoon is disposed in the jugular vein, above the subclavian vein (s8).

The guide wire can be pulled out and the sheath is fixated to the skinin a location that allows the maximal axial adjustment of the assembly.After the fixation, the centralizer is positioned, and an electric cableis connected (s9). The motor is activated (e.g., using a controller thatcan be accessed via a console graphical user interface (GUI)) and causesthe distal and proximal balloons to inflate. The distal balloon can beinflated prior to inflating the proximal balloon. The CVP can bemeasured through a sheath luer. The pressure can be adjusted using acatheter handle by bringing the proximal assembly closer to the sheathor away from the sheath (or any other mechanism) (s10). The motor candrive the impeller to induce the low pressure zone by causing fluid tobe pumped through the catheter. In this way, the system can operateautomatically to keep the low pressure zone (or “isolated zone”) at anominal pressure value of, for example, 2.5±2.5 mmHg. This can be donebe controlling the motor RPM.

In general, the described catheter system is configured to seal a zoneat the bifurcation of the patient's jugular and subclavian veins usingthe distal and proximal balloons. As the impeller is operated, the bloodis directed from the low pressure zone such that the pressure insidethat zone is reduced. The motor receives feedback from one or morepressure sensors, and the pressure can be regulated by the motor RPM.The CVP can be adjusted by a regulation mechanism at the proximalassembly.

As discussed above, a catheter can include proximal and distalrestrictors. Also, a catheter can include can only one selectivelydeployable restriction member or restrictor, for example, a restrictorthat corresponds to a proximal restrictor. Furthermore, the inventorshave surprisingly discovered that a single restriction member or anothersimilar component can be used to restrict a blood flow in a vein tocontrol pressure distally of the restrictor and throughout the venoussystem. In some embodiments, the restrictor can be a proximalrestrictor. It should be appreciated that the single restrictor isreferred to herein as a “proximal” restrictor because it is placedproximally of an outflow port of a duct. This can be the same or similarlocation at which a proximal restrictor of a two-restrictor catheterhaving distal and proximal restrictors can be placed. Inflation of asingle restrictor (which can include an inflatable balloon) allowsreaching a working point of a low pressure reading in a venous angle(lymphatic outflow) pressure sensor.

The embodiments where the catheter includes a single restrictor do notrequire a pump or other suction device. Rather, the heart during thediastolic filling phase acts as a suction pump and needs to be filled bya certain amount of blood at certain time duration (diastole). Thevenous system acts as a filling reservoir for the right heart to pumpblood in. Because part of the venous system is constricted via acatheter's single restrictor, the heart needs to pump in harder andreduce its pressures in order to fill in the same amount of blood.

Accordingly, in some embodiments, to reduce venous pressure locally,such as at the thoracic duct outflow or systemically throughout thevenous system, a single selectively deployable restrictor can be placedin a vein in a patient's body such that it completely or partiallyblocks a blood flow through that vein. The vein should be a relativelylarge vein that has blood flow from about 300 mm/min to about 500mm/min. The inventors have surprisingly discovered that implanting acatheter with a single restrictor in a vein results in a reduction ofthe pressures during the diastolic filling phase of the ventricle andenables local vein pressure reduction. For example, in at least someembodiments, a catheter including an inflatable balloon or other type ofrestrictor with a controlled tunnel or lumen extending therethrough canbe placed in the jugular vein and activated to allow the flow from thejugular vein through it and thus reduce the pressures at the thoracicduct outflow.

FIG. 48 illustrates schematically a portion of the venous system of apatient where a catheter can be implanted. The system includes athoracic duct 801, a left subclavian vein 805, an innominate vein 807, aright atrium 811, a right ventricle 815, an inferior vena cava 819, asuperior vena cava 823, a right subclavian vein 827, a lymphatic duct831, a right internal jugular vein 835, and a left internal jugular vein839. Methods of the invention include reducing pressure at an outflow ofa duct by positioning, in a blood vessel in a region 865 near an outputof a duct, a device comprising a tapered lumen and pumping blood from awide end of the tapered lumen to a narrow end to thereby lower pressurenear the output of the duct.

Normal venous physiology and pressures are illustrated. Thus, pressureareas having P1 pressure and P2 pressure are indicated. Normal bloodpressure measured at a patient supine position is as follows: P1 isapproximately 5 mm Hg and P2 is approximately 3 mm Hg. At a heartfailure (supine position), P1 is approximately 15 mm Hg and P2 isapproximately 13 mm Hg. Methods of the disclosure reduce pressure atleast at the region 865 near an output of a duct so that the pressure iscloser to 5 mm Hg than to 15 mm Hg.

FIG. 49 illustrates schematically the portion of the patient's venoussystem (as also shown in FIG. 48 ), with a catheter system 701 having asingle selectively deployable restrictor 719 and a flexible membrane 715and disposed in the left internal jugular vein to decrease the pressuresdistally of the restrictor 719. The system 701 includes an impellerassembly 711 disposed at a distal portion 722 of the catheter shaft 719.The flexible membrane 715 is connected to the distal portion 722 of thecatheter shaft 719 (e.g., optionally to the impeller assembly). Therestrictor 715 is configured to restrict blood flow within the vein whenthe restrictor is activated, and the restrictor includes a balloon thatis configured to be inflated. In some embodiments, the restrictordisposed in a vein may not restrict the blood flow entirely—e.g., aboutone third, or other portion, of the flow can be restricted. The amountof the reduction in blood flow through the vein can depend on a desiredreduction of blood pressure. Pressure upstream and downstream of thesingle restriction member is monitored using suitable sensors, such asblood pressure sensors.

The catheter system having a single selectively deployable restrictorcan be configured in many various ways and it can include componentssimilar to any of the components described herein in connection withFIG. 1 through FIG. 47 . However, the catheter system with a singleselectively deployable restrictor differs from two-restrictor cathetersystems. For example, it does not include a suction pump, and othercomponents included in a two-restrictor catheter can be omitted ormodified. The single selectively deployable restrictor can be configuredin many various ways and using suitable materials, including thematerials described hereinabove. Also, the catheter system with a singleselectively deployable restrictor can be implanted in a vein usingvarious techniques.

The single selectively deployable restrictor is configured to control avolume of fluid from an upstream side of the restrictor to a downstreamside (towards the heart) of the restrictor member to cause a pumpingforce of the heart during diastole to be increased to thereby causepressure at the downstream side to be decreased. The catheter systemdoes not include a suction pump and the heart acts as such a pump.

In some embodiments, the catheter has a flexible membrane having aballoon coupled to at least a portion thereof and having a lumen ortunnel extending therethrough. When the balloon is activated to beexpanded, this also causes the membrane to expand, e.g., the membrane ismoved from a relaxed configuration to an activated configuration. Inthis way, the membrane in the activated configuration (e.g., as shown inFIG. 49 ) defines a lumen or tunnel formed in a controller manner. Inthe illustrated embodiments, the balloon can be configured so as toconstrict the membrane in the activated configuration, which can cause adiameter of the tunnel of the membrane to be decreased. For example,when the balloon is expanded within a vein, the balloon becomesconstricted by the inner wall of the vein. The balloon can be expandeduntil it is in an expanded configuration in which it constricts themembrane to thus decrease a size of the tunnel through the membrane to adesired size. The diameter of the tunnel can be much smaller than thatof a vessel (e.g., a jugular vein or an innominate vein) in which thecatheter is placed. For example, in at least some embodiments, thediameter of the tunnel can be in a range of from about 2 mm to about 4mm. Also, in some embodiments, the diameter of the tunnel can be in arange of from about 1 to 4 mm.

When the catheter including a single selectively deployable restrictoris disposed in a vein and the restrictor is activated, the singlerestrictor provides, in combination with other components, occlusionwithin the vein. The catheter is configured such that, when its singlerestrictor at least partially occludes the vein, fluid is allowed toflow through the catheter so as to cause the heart during its diastolicphase to pump blood in harder in order to refill again. The catheter caninclude a lumen or tunnel extending through the restrictor (which can bea lumen extending through a flexible membrane to which the restrictor iscoupled or a lumen formed in a catheter's shaft) that allows fluid toflow therethrough. The tunnel acts as a restrictor that forces the heartto pump in blood harder such that the diastolic suction forces of theheart are increased. This causes a decrease in the pressure in the heartduring the diastolic phase when the heart is sucking blood in from thesurrounding veins and thus the end diastolic volume of the right heartis preserved and the preload to the heart is lowered. In this way, thepressure can be reduced anywhere in the venous system (and the lymphaticoutflow) by introducing a catheter with a balloon or any other type ofan adjustable restrictor. Thus, a low pressure region can be created inparts of the patient's venous system except a part of the patient'svenous system upstream of the single restrictor.

Accordingly, the restrictor placed distally towards the heart can beactivated to greatly reduce the pressure as a function of the restrictorsize (which can be adjustable) and the operation of the heart. Thecatheter can be configured to be used for a short time such, or thecatheter can be implanted such that it remains implanted in a patient'sbody for several days or weeks.

In some embodiments, a diameter of the catheter shaft can be from about4 Fr (French units) to about 9 Fr, and the catheter can include acompliant balloon and an internal membrane that has a lumen having adiameter in a range of from about 1 mm to about 4 mm. The operation ofthe catheter can be controlled and it can be placed at the left internaljugular vein or the right internal jugular vein, or at other locationsin the venous system.

Referring back to FIG. 49 , when the catheter with the restrictor isplaced as shown, during the diastolic phase, pressure P2<pressure PI,and pressure P3<pressure P2. The pressure PI is measure upstream orproximally of the catheter, the pressure P2 is measured downstream ordistally of the catheter and in other parts of the venous system, andthe pressure P3 is measured at the heart. In these embodiments, a higherpressure zone is proximal to the proximal restrictor, and a low pressurezone is distal to the proximal restrictor. Moreover, as shown in FIG. 49, a higher pressure zone (PI) is proximal to the proximal restrictor anda low pressure zone (P2) includes other parts of the venous system,except the part that is upstream of the restrictor where the pressure isPI.

FIG. 50 illustrates schematically examples of possible locations of thecatheter and restrictor 719 within a patient's body. For example, thecatheter, which can be implantable, can be disposed in the rightsubclavian vein, left subclavian vein, right internal jugular vein, leftinternal jugular vein, and inferior vena cava. Also, in someembodiments, the catheter can be disposed at the femoral vein.

The catheter can have any suitable configuration. In some embodiments,as shown in an embodiment of FIG. 51 , a catheter includes a singleselectively deployable restriction member or restrictor, a shaft, and aflexible membrane that is generally tubular in this illustratedembodiment. The shaft can have one or more lumens extendingtherethrough. For example, as shown in FIG. 51 , it can have a centrallumen and at least one pressure sensing lumen that can have proximal anddistal pressure sensors. Also, in some embodiments, one or more pressuresensors can be associated with the central lumen.

The restrictor is attached to the membrane and surrounds the membraneand the shaft. In the example in FIG. 51 , the single selectivelydeployable restriction member is formed over a portion of the flexiblemembrane at substantially a midpoint between a proximal end of theflexible membrane and a distal end of the flexible membrane. Theflexible membrane can be assembled to the catheter (e.g., coupled to theshaft) in any of a number of ways to enable the flexible membrane toform an ovoid, kidney, or another shape upon expansion of the flexiblemembrane (as a result of activating the restrictors) so that blood canbe transported from a position within the vein proximal to therestrictor to a point distal to the restrictor. The membrane can beattached, e.g., bonded or welded, around a partial portion (such as anon-zero portion that is less than 360° of the catheter shaft'scircumference) or full portion (360° around the catheter shaft'scircumference) of the circumference of the catheter's shaft, such as ina range of about 10° to 360° of the shaft's circumference.

In FIG. 51 , the flexible membrane is attached to a portion of thecatheter shaft circumference. The restrictor can be bonded or welded toan outer surface of the flexible membrane so that the restrictorsurrounds the outer circumference of the catheter and the flexiblemembrane. As discussed above, the restrictor can have features thatfacilitate its attachment to the membrane.

The membrane can have many various configurations, including any of themembrane configurations described herein. As also shown in FIG. 51 , themembrane can have holes or openings that allow fluid to flow under therestrictor. It should be appreciated that the openings are shown in theproximal and distal ends of the membrane by way of example only, as asuitable number of openings can be formed at any suitable locations inthe membrane. The membrane can have any suitable size. For example, asshown in FIG. 51 , the membrane can have a diameter in a range of fromabout 4 mm to about 10 mm.

The restrictor can also have various configurations. In the exampleillustrated, as shown in FIG. 51 through FIG. 32 , the restrictorincludes an inflatable balloon. The restrictor and the balloon can beconfigured similar to any of the restrictors and balloons describedherein, though the described configurations can be modified. The balloonis configured to be inflated such that in a relaxed configuration theballoon is not inflated and in the activated configuration the balloonis inflated. The balloon can be inflated similar to the manner describedabove (e.g., using an inflation lumen, etc.), or in any other manner.For example, the catheter can include at least one inflation lumenthrough which an inflation fluid (e.g., air, liquid, etc.) can beintroduced to inflate/deflate the balloon.

The diameter of the balloon can be from about 8 mm to about 20 mm. Asindicated in FIG. 51 , the balloon is shown in an activated or inflatedconfiguration in which it partially restricts the blood flow through themembrane. As shown, in this example, the balloon is configured such thatits portions surrounding the membrane have omega-like shapes, though theballoon can have other shapes that deviate from a circle. For example,in at least some embodiments, the balloon can be configured similar torestriction member 502 in FIG. 17 . The balloon may not be mounted onthe membrane as a full circle such that, when the balloon is inflated,some of its portions are irregularly shaped—e.g., it can at leastpartially bulge inwardly, towards the membrane, thus causing a diameterof the flexible membrane to reversibly decrease. The balloon can beconfigured to be able to bulge inwardly in many different ways. Theinflation of the balloon can be controlled using one or more suitablesensors (e.g., pressure sensors) monitoring pressure upstream anddownstream of the balloon. Because the amount of the blood flow allowedthrough the catheter (which affects the increase in the diastolicsuction forces of the heart), depends on the degree of the inflation ofthe balloon, the degree of the inflation is controlled based on theblood pressure being monitored.

FIG. 52 and FIG. 31B illustrate the balloon when it fully restricts themembrane. In use, the balloon can be in any configuration that can bebetween the configuration in FIG. 51 in which the balloon partiallyrestricts the membrane and the configuration in FIG. 52 and FIG. 31B inwhich the balloon fully restricts the membrane. The balloon can becontrolled to be selectively expanded so as to at least partiallyconstrict the membrane to form a tunnel therethrough that causes theheart to pump blood in harder. As a result, pressure in the area distalto the balloon is reduced.

FIG. 54 through FIG. 56 illustrate schematically a process of activationof a balloon and a flexible membrane coupled thereto which forms a lumenfor blood flow. As discussed before, the balloon at least partiallyencompasses the flexible membrane coupled to a catheter shaft. The shaftwith the membrane and the balloon is shown to be disposed within a vein.FIG. 54 illustrates the shaft, membrane, and balloon prior to activationor inflation of the balloon. In FIG. 55 , the balloon is inflated tosome degree such that it contacts the vein wall, and the membranecoupled to and at least partially surrounded by the balloon forms ablood flow lumen. As shown, the balloon can be inflated such that one ormore bulges or other features are formed about an outer wall of themembrane. FIG. 56 shows that the balloon is inflated further so as toconstrict the membrane further and to thus decrease a diameter of ablood flow lumen in the membrane. The balloon is inflated further so asto form at least one bulging feature compressing the membrane, as shownschematically in FIG. 56 . Thus, the blood flow lumen in FIG. 56 issmaller than the blood flow lumen in FIG. 55 . In some embodiments, adiameter of the blood flow lumen as shown in FIG. 56 (which can be anaverage diameter, since the lumen may not be uniformly shaped throughoutits circumference) can be in a range of from about 1 mm to about 4 mm.

A distal portion of the catheter system, e.g., a distal end of the shaft(FIG. 51 ), which can have an atraumatic tip, in the initialconfiguration can be inserted into the jugular vein of the patient,which is the left internal jugular vein in this embodiment of FIG. 51 .After positioning the catheter within the patient, the restrictor can beexpanded, e.g., moved from its relaxed configuration to its activatedconfiguration. The expansion of the restrictor also expands the flexiblemembrane, e.g., moves the flexible membrane from a relaxed configurationto an activated configuration. Moreover, because of the configuration ofthe restrictor (e.g., it has one or more bulging or other features), theexpanded membrane is constricted so as to form a lumen or tunneltherethrough of a certain size. The size of the tunnel can be controlledby adjusting a degree of the inflation of the balloon, which can be doneusing a suitable controller. Pressure can be monitored using suitablesensors (e.g., blood pressure sensors), which can be associated withpressure sensor lumens, to determine when a desired decrease between thepressure proximal to the catheter and the pressure distal to thecatheter is achieved. Pressure upstream and downstream of the restrictorcan be monitored.

With reference to FIG. 51 , blood now flows from the jugular vein intothe flexible membrane and flows therethrough to the innominate vein. Theexpansion of the restrictor occludes a portion of the vein in which thecatheter is deployed, and, thus, an area proximate to the catheterbecomes a low pressure zone. No suction pump or a similar device may berequired because the patient's heart itself functions as a pump duringits normal operation. In particular, as mentioned above, the heartduring the diastolic filling phase acts as a suction pump. The venoussystem acts as a filling reservoir for the right heart to pump blood in.Because part of the venous system is constricted by the catheter, theheart needs to pump in harder, which results in reduction of thepressure in the venous system, as shown by way of example in FIG. 49 .

FIG. 57 illustrates another embodiment of a catheter system having aproximal restriction member or restrictor including an expandableballoon. The catheter system can be configured similarly to a portion ofthe catheter system with a proximal balloon shown in FIG. 33 . In thisexample, blood can flow through a lumen formed in a catheter's shaft.Blood can flow through the balloon as shown schematically in FIG. 57 .The balloon is configured to be activated to become expanded, and in anexpanded configuration it at least partially occludes a vein in whichthe catheter system is placed. A shaft of the catheter system has alumen extending therethrough and communicating with a lumen extendingthrough the balloon. Fluid flow through the lumen of the catheter systemof FIG. 57 can be regulated using a flow regulator component similar tothat shown in FIG. 24 , and/or other flow regulator component(s) (e.g.,a plunger). Thus, the lumen can be controlled to thus control reductionin blood pressure that can be achieved by causing the heart to pump inblood harder during diastole.

In FIG. 57 , a knob can be configured to be operated to move a plungeror other component configured to close and open the lumen extendingthrough the balloon to regulate blood flow. An eyelet is configured tofacilitate securement of the catheter system to a patient during use.The catheter shaft can be locked in position using, for example, a TuohyBorst valve. The Tuohy Borst valve or hemostasis septum can be used toprevent blood from coming in the opposite direction. The catheter canhave any other suitable components.

In use, the catheter is introduced into the vein (as shown, e.g., inFIG. 49 ), e.g., using a guidewire extending through the central lumen.In an initial configuration, the catheter's restrictor has the balloonis in a non-inflated configuration. The catheter can be delivered to theinsertion site in a compressed configuration. For example, it can bereleasably disposed within a sheath. Thus, the shaft of the catheterencircled by a compressed flexible membrane that is in turn surroundedby the compressed restriction member can be delivered to a desiredlocation in a vein in a patient's body. The catheter can be advanced outof the sheath to position the catheter as shown in FIG. 49 .

FIG. 58 through FIG. 61 illustrate additional examples of a catheterhaving a single restriction member. In particular, FIG. 58 shows acatheter having a catheter shaft and an expandable balloon disposed at adistal end of the catheter. The catheter shaft can have four lumens,such as a central lumen for fluid flow, a distal sensor lumen, a ballooninflation lumen, and a proximal sensor lumen. The catheter shown in FIG.58 has a plunger or other similar component configured to control anamount of fluid allowed to be transmitted through the central lumen, byreversibly occluding proximal (suction) inlets formed through theshaft's sidewall proximally to the balloon. The inlets are incommunication with the lumen so as to allow fluid to enter thecatheter's lumen therethrough, as shown in FIG. 58 by four arrows at theproximal suction inlet pointing inward toward the lumen catheter. Theproximal inlets can include any number of openings formed through theshaft's sidewall. The openings can have any of a variety ofconfigurations, e.g., slits, circular holes, ovular holes, rectangularslots, etc. The number, position, and configuration of the inlets andthe configuration of the adjustable plunger enable the regulation of theflow which is directed into the catheter. As shown in FIG. 58 , thefluid flow is directed into and through the catheter shaft and it leavesthe catheter from a tip or one or more openings distal to the balloon.

FIG. 59 shows an embodiment of a catheter having a single selectivelydeployable restriction member and a flexible membrane. FIG. 60illustrates another embodiment of a catheter having a single selectivelydeployable restriction member and a flexible membrane. The catheters inFIG. 59 and FIG. 60 can be similar to the catheters described above, forexample, those shown in FIG. 51 , FIG. 52 , and FIG. 31B, thoughdifferent components can be used additionally or alternatively. In thecatheters shown in FIG. 59 and FIG. 60 , the restriction member has anexpandable balloon mounted over a collapsible membrane and a shaft. Oncethe catheter is positioned in a vein, the balloon is activated to beexpanded. In the expanded or inflated configuration, the balloon can bepressed against the wall of the vein. The flexible membrane is alsoactivated and defines a lumen for passage of blood therethrough. Furtherinflation of the balloon causes the balloon to be further constricted bythe vein wall, which causes the lumen in the membrane to be decreased. Asize of the lumen can be adjusted to cause the diastolic suction forcesof the heart to be increased so as to create a low pressure zone in adownstream side of the restriction member.

FIG. 61 illustrates another embodiment of a catheter having a singleselectively deployable restriction member and a flexible membrane. Inthis embodiment, the flexible membrane is coupled to a sheath such thatthe membrane remains coupled to the sheath when the catheter ispositioned in a vein. The flexible membrane has inlet opening formedthrough a side wall thereof. The catheter is configured such that ablood flow through a lumen formed in the membrane is controlled byadjusting a number of the inlet openings that are open and closed.

This is done by advancing and retracting the catheter relative to thesheath, to vary a number of the inlet openings that are open and closed.

It should be appreciated that the catheters shown in FIG. 58 throughFIG. 61 can include other suitable components not shown for the sake ofsimplicity. For example, the catheters can have components configured tomeasure pressure upstream and downstream of the balloon.

The catheter systems described in connection with FIG. 48 through FIG.61 provide various advantages over existing systems. For example, thesystems include a reduced number of components—a single selectivelydeployable restrictor is used, and the use of many components (e.g.,suction pumps) included a two-restrictor catheter system can be avoided.This simplifies the catheter system, its operation, use, andmaintenance. Also, a lumen having blood flowing therethrough is formedin a controlled manner, with the size of the lumen determining at leastin part a magnitude of the pressure reduction in the venous system. Thepressure reduction can be achieved not only downstream of therestrictor, but in other parts throughout the venous system by placingthe catheter in a vein.

The catheter system with a single restriction member can be placed in apatient's body for a relatively short amount of time, e.g., severalhours. Also, the catheter system can be configured to be implanted in apatient's body for a longer duration of time (e.g., several days) andthe catheter can be controlled to be selectively activated anddeactivated.

A person skilled in the art will appreciate that the systems and methodsdisclosed herein can be used with a variety of surgical devices,including measuring devices, sensing devices, locator devices, insertiondevices, etc.

One skilled in the art will appreciate further features and advantagesof the described subject matter based on the above-describedembodiments. Accordingly, the present disclosure is not to be limited bywhat has been particularly shown and described, except as indicated bythe appended claims. All publications and references cited herein areexpressly incorporated herein by reference in their entirety.

What is claimed is:
 1. A catheter system comprising: a catheterdimensioned for insertion into a blood vessel, the catheter comprising adistal portion having an inlet and an outlet; and a deployablerestrictor comprising a balloon attached to the distal portion, wherein,when the restrictor is in a deployed configuration, a portion of therestrictor defines a tapered surface that directs fluid from the bloodvessel into the inlet.
 2. The system of claim 1, further comprising anassembly for receiving the distal portion of the catheter, the assemblycomprising a proximal end that is external to the blood vessel when thesystem is in use.
 3. The system of claim 2, wherein the assemblycomprises a second restrictor attached to a distal end of said assembly.4. The system of claim 3, wherein the restrictor and the secondrestrictor are separately movable inside the blood vessel.
 5. The systemof claim 1, wherein the distal portion of the catheter comprises animpeller assembly with an impeller disposed therein.
 6. The system ofclaim 5, wherein the impeller assembly comprises the inlet and theoutlet.
 7. The system of claim 5, wherein the restrictor is mountedaround the impeller assembly.
 8. The system of claim 5, wherein at leasta portion of the impeller is distal to the restrictor.
 9. The system ofclaim 5, wherein, when the restrictor is deployed and the impeller isactivated inside the blood vessel, fluid is directed by the taperedsurface of the restrictor into the inlet and is drawn through theassembly and out the outlet by the impeller.
 10. The system of claim 1,wherein the blood vessel is one of an internal jugular vein, asubclavian vein, or an innominate vein.
 11. The system of claim 1,wherein the catheter comprises a diameter of between 9 and 15 Fr. 12.The system of claim 5, wherein, when the restrictor is deployed and theimpeller is activated, fluid pressure upstream of the restrictor isreduced.